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XCCDF
CloudLinux AlmaLinux OS 9 Security Technical Implementation Guide
Profiles
II - Mission Support Sensitive
II - Mission Support Sensitive
An XCCDF Profile
Details
Items
Prose
445 rules organized in 445 groups
SRG-OS-000027-GPOS-00008
1 Rule
AlmaLinux OS 9 must limit the number of concurrent sessions to ten for all accounts and/or account types.
Low Severity
Operating system management includes the ability to control the number of users and user sessions that use an operating system. Limiting the number of allowed users and sessions per user is helpful in reducing the risks related to denial-of-service (DoS) attacks. This requirement addresses concurrent sessions for information system accounts and does not address concurrent sessions by single users via multiple system accounts. The maximum number of concurrent sessions should be defined based upon mission needs and the operational environment for each system.
SRG-OS-000031-GPOS-00012
1 Rule
AlmaLinux OS 9 must automatically lock graphical user sessions after 15 minutes of inactivity.
Medium Severity
A session lock is a temporary action taken when a user stops work and moves away from the immediate physical vicinity of the information system but does not log out because of the temporary nature of the absence. The session lock is implemented at the point where session activity can be determined. The operating system session lock event must include an obfuscation of the display screen so as to prevent other users from reading what was previously displayed. Publicly viewable images can include static or dynamic images, for example, patterns used with screen savers, photographic images, solid colors, a clock, a battery life indicator, or a blank screen, with the additional caveat that none of the images convey sensitive information.
SRG-OS-000031-GPOS-00012
1 Rule
AlmaLinux OS 9 must conceal, via the session lock, information previously visible on the display with a publicly viewable image.
Medium Severity
Setting the screensaver mode to blank-only conceals the contents of the display from passersby.
SRG-OS-000031-GPOS-00012
1 Rule
AlmaLinux OS 9 must prevent a user from overriding the session idle-delay setting for the graphical user interface.
Medium Severity
A session lock is a temporary action taken when a user stops work and moves away from the immediate physical vicinity of the information system but does not log out because of the temporary nature of the absence. The session lock is implemented at the point where session activity can be determined. The operating system session lock event must include an obfuscation of the display screen so as to prevent other users from reading what was previously displayed. Publicly viewable images can include static or dynamic images, for example, patterns used with screen savers, photographic images, solid colors, a clock, a battery life indicator, or a blank screen, with the additional caveat that none of the images convey sensitive information.
SRG-OS-000029-GPOS-00010
1 Rule
AlmaLinux OS 9 must initiate a session lock for graphical user interfaces when the screensaver is activated.
Medium Severity
A session lock is a temporary action taken when a user stops work and moves away from the immediate physical vicinity of the information system but does not want to logout because of the temporary nature of the absence.
SRG-OS-000029-GPOS-00010
1 Rule
AlmaLinux OS 9 must prevent a user from overriding the session lock-delay setting for the graphical user interface.
Medium Severity
A session time-out lock is a temporary action taken when a user stops work and moves away from the immediate physical vicinity of the information system but does not logout because of the temporary nature of the absence. Rather than relying on the user to manually lock their operating system session prior to vacating the vicinity, the GNOME desktop can be configured to identify when a user's session has idled and take action to initiate the session lock. As such, users should not be allowed to change session settings.
SRG-OS-000029-GPOS-00010
1 Rule
AlmaLinux OS 9 must automatically exit interactive command shell user sessions after 10 minutes of inactivity.
Medium Severity
Terminating an idle interactive command shell user session within a short time period reduces the window of opportunity for unauthorized personnel to take control of it when left unattended in a virtual terminal or physical console. Declaring $TMOUT as read-only means the user cannot override the setting. Satisfies: SRG-OS-000029-GPOS-00010, SRG-OS-000281-GPOS-00111, SRG-OS-000163-GPOS-00072
SRG-OS-000028-GPOS-00009
1 Rule
AlmaLinux OS 9 must be able to directly initiate a session lock for all connection types using smart card when the smart card is removed.
Medium Severity
A session lock is a temporary action taken when a user stops work and moves away from the immediate physical vicinity of the information system but does not want to log out because of the temporary nature of the absence. The session lock is implemented at the point where session activity can be determined. Regardless of where the session lock is determined and implemented, once invoked, the session lock must remain in place until the user re-authenticates. No other activity aside from re-authentication must unlock the system.
SRG-OS-000028-GPOS-00009
1 Rule
AlmaLinux OS 9 must prevent a user from overriding the disabling of the graphical user smart card removal action.
Medium Severity
A session lock is a temporary action taken when a user stops work and moves away from the immediate physical vicinity of the information system but does not want to log out because of the temporary nature of the absence. The session lock is implemented at the point where session activity can be determined. Regardless of where the session lock is determined and implemented, once invoked, the session lock must remain in place until the user re-authenticates. No other activity aside from re-authentication must unlock the system.
SRG-OS-000032-GPOS-00013
1 Rule
AlmaLinux OS 9 must log SSH connection attempts and failures to the server.
Medium Severity
Remote access services, such as those providing remote access to network devices and information systems, which lack automated monitoring capabilities, increase risk, and make remote user access management difficult at best. Remote access is access to DOD nonpublic information systems by an authorized user (or an information system) communicating through an external, nonorganization-controlled network. Remote access methods include, for example, dial-up, broadband, and wireless. Automated monitoring of remote access sessions allows organizations to detect cyber attacks and also ensure ongoing compliance with remote access policies by auditing connection activities of remote access capabilities, such as Remote Desktop Protocol (RDP), on a variety of information system components (e.g., servers, workstations, notebook computers, smartphones, and tablets). SSH provides several logging levels with varying amounts of verbosity. "DEBUG" is specifically not recommended other than strictly for debugging SSH communications since it provides so much data that it is difficult to identify important security information. "INFO" or "VERBOSE" level is the basic level that only records login activity of SSH users. In many situations, such as Incident Response, it is important to determine when a particular user was active on a system. The logout record can eliminate those users who disconnected, which helps narrow the field.
SRG-OS-000032-GPOS-00013
1 Rule
All AlmaLinux OS 9 remote access methods must be monitored.
Medium Severity
Remote access services, such as those providing remote access to network devices and information systems, which lack automated monitoring capabilities, increase risk, and make remote user access management difficult at best. Remote access is access to DOD nonpublic information systems by an authorized user (or an information system) communicating through an external, nonorganization-controlled network. Remote access methods include, for example, dial-up, broadband, and wireless. Automated monitoring of remote access sessions allows organizations to detect cyber attacks and also ensure ongoing compliance with remote access policies by auditing connection activities of remote access capabilities, such as Remote Desktop Protocol (RDP), on a variety of information system components (e.g., servers, workstations, notebook computers, smartphones, and tablets). Monitoring of remote access can be used to spot attacks such as brute-force authentication attempts and denial-of-service (DoS) attacks.
SRG-OS-000250-GPOS-00093
1 Rule
AlmaLinux OS 9 SSH client must be configured to use only encryption ciphers employing FIPS 140-3 validated cryptographic hash algorithms to protect the confidentiality of SSH client connections.
Medium Severity
Without cryptographic integrity protections, information can be altered by unauthorized users without detection. Remote access (e.g., RDP) is access to DOD nonpublic information systems by an authorized user (or an information system) communicating through an external, nonorganization-controlled network. Remote access methods include, for example, dial-up, broadband, and wireless. Cryptographic mechanisms used for protecting the integrity of information include, for example, signed hash functions using asymmetric cryptography enabling distribution of the public key to verify the hash information while maintaining the confidentiality of the secret key used to generate the hash. AlmaLinux OS 9 incorporates systemwide crypto policies by default. The SSH configuration file has no effect on the ciphers, MACs, or algorithms unless specifically defined in the /etc/sysconfig/sshd file. The employed algorithms can be viewed in the /etc/crypto-policies/back-ends/opensshserver.config file.
SRG-OS-000250-GPOS-00093
1 Rule
AlmaLinux OS 9 must implement DOD-approved encryption ciphers to protect the confidentiality of SSH client connections.
Medium Severity
Without cryptographic integrity protections, information can be altered by unauthorized users without detection. Remote access (e.g., RDP) is access to DOD nonpublic information systems by an authorized user (or an information system) communicating through an external, nonorganization-controlled network. Remote access methods include, for example, dial-up, broadband, and wireless. Cryptographic mechanisms used for protecting the integrity of information include, for example, signed hash functions using asymmetric cryptography enabling distribution of the public key to verify the hash information while maintaining the confidentiality of the secret key used to generate the hash. AlmaLinux OS 9 incorporates systemwide crypto policies by default. The SSH configuration file has no effect on the ciphers, MACs, or algorithms unless specifically defined in the /etc/sysconfig/sshd file. The employed algorithms can be viewed in the /etc/crypto-policies/back-ends/opensshserver.config file.
SRG-OS-000250-GPOS-00093
1 Rule
AlmaLinux OS 9 SSH client must be configured to use only Message Authentication Codes (MACs) employing FIPS 140-3 validated cryptographic hash algorithms.
Medium Severity
Without cryptographic integrity protections, information can be altered by unauthorized users without detection. Remote access (e.g., RDP) is access to DOD nonpublic information systems by an authorized user (or an information system) communicating through an external, nonorganization-controlled network. Remote access methods include, for example, dial-up, broadband, and wireless. Cryptographic mechanisms used for protecting the integrity of information include, for example, signed hash functions using asymmetric cryptography enabling distribution of the public key to verify the hash information while maintaining the confidentiality of the secret key used to generate the hash. AlmaLinux OS 9 incorporates systemwide crypto policies by default. The SSH configuration file has no effect on the ciphers, MACs, or algorithms unless specifically defined in the /etc/sysconfig/sshd file. The employed algorithms can be viewed in the /etc/crypto-policies/back-ends/opensshserver.config file.
SRG-OS-000250-GPOS-00093
1 Rule
AlmaLinux OS 9 must implement DOD-approved encryption ciphers to protect the confidentiality of SSH server connections.
Medium Severity
Without cryptographic integrity protections, information can be altered by unauthorized users without detection. Remote access (e.g., RDP) is access to DOD nonpublic information systems by an authorized user (or an information system) communicating through an external, nonorganization-controlled network. Remote access methods include, for example, dial-up, broadband, and wireless. Cryptographic mechanisms used for protecting the integrity of information include, for example, signed hash functions using asymmetric cryptography enabling distribution of the public key to verify the hash information while maintaining the confidentiality of the secret key used to generate the hash.
SRG-OS-000250-GPOS-00093
1 Rule
AlmaLinux OS 9 SSH server must be configured to use only FIPS 140-3 validated key exchange algorithms.
Medium Severity
Without cryptographic integrity protections provided by FIPS-validated cryptographic algorithms, information can be viewed and altered by unauthorized users without detection. AlmaLinux OS 9 incorporates systemwide crypto policies by default. The SSH configuration file has no effect on the ciphers, MACs, or algorithms unless specifically defined in the /etc/sysconfig/sshd file. The employed algorithms can be viewed in the /etc/crypto-policies/back-ends/opensshserver.config file. The system will attempt to use the first algorithm presented by the client that matches the server list. Listing the values "strongest to weakest" is a method to ensure the use of the strongest algorithm available to secure the SSH connection.
SRG-OS-000250-GPOS-00093
1 Rule
AlmaLinux OS 9 must implement DOD-approved systemwide cryptographic policies to protect the confidentiality of SSH server connections.
Medium Severity
Without cryptographic integrity protections, information can be altered by unauthorized users without detection. Remote access (e.g., RDP) is access to DOD nonpublic information systems by an authorized user (or an information system) communicating through an external, nonorganization-controlled network. Remote access methods include, for example, dial-up, broadband, and wireless. Cryptographic mechanisms used for protecting the integrity of information include, for example, signed hash functions using asymmetric cryptography enabling distribution of the public key to verify the hash information while maintaining the confidentiality of the secret key used to generate the hash.
SRG-OS-000250-GPOS-00093
1 Rule
AlmaLinux OS 9 SSH server must be configured to use only Message Authentication Codes (MACs) employing FIPS 140-3 validated cryptographic hash algorithms.
Medium Severity
Without cryptographic integrity protections, information can be altered by unauthorized users without detection. Remote access (e.g., RDP) is access to DOD nonpublic information systems by an authorized user (or an information system) communicating through an external, nonorganization-controlled network. Remote access methods include, for example, dial-up, broadband, and wireless. Cryptographic mechanisms used for protecting the integrity of information include, for example, signed hash functions using asymmetric cryptography enabling distribution of the public key to verify the hash information while maintaining the confidentiality of the secret key used to generate the hash. AlmaLinux OS 9 incorporates systemwide crypto policies by default. The SSH configuration file has no effect on the ciphers, MACs, or algorithms unless specifically defined in the /etc/sysconfig/sshd file. The employed algorithms can be viewed in the /etc/crypto-policies/back-ends/opensshserver.config file.
SRG-OS-000033-GPOS-00014
1 Rule
AlmaLinux OS 9 must force a frequent session key renegotiation for SSH connections to the server.
Medium Severity
Without confidentiality protection mechanisms, unauthorized individuals may gain access to sensitive information via a remote access session. Remote access is access to DOD nonpublic information systems by an authorized user (or an information system) communicating through an external, nonorganization-controlled network. Remote access methods include, for example, dial-up, broadband, and wireless. Encryption provides a means to secure the remote connection to prevent unauthorized access to the data traversing the remote access connection (e.g., RDP), thereby providing a degree of confidentiality. The encryption strength of a mechanism is selected based on the security categorization of the information. Session key regeneration limits the chances of a session key becoming compromised.
SRG-OS-000250-GPOS-00093
1 Rule
AlmaLinux OS 9 must implement DOD-approved TLS encryption in the GnuTLS package.
High Severity
Without cryptographic integrity protections, information can be altered by unauthorized users without detection. Remote access (e.g., RDP) is access to DOD nonpublic information systems by an authorized user (or an information system) communicating through an external, nonorganization-controlled network. Remote access methods include, for example, dial-up, broadband, and wireless. Cryptographic mechanisms used for protecting the integrity of information include, for example, signed hash functions using asymmetric cryptography enabling distribution of the public key to verify the hash information while maintaining the confidentiality of the secret key used to generate the hash.
SRG-OS-000033-GPOS-00014
1 Rule
AlmaLinux OS 9 IP tunnels must use FIPS 140-3 approved cryptographic algorithms.
Medium Severity
Overriding the system crypto policy makes the behavior of the Libreswan service violate expectations and makes the system configuration more fragmented.
SRG-OS-000250-GPOS-00093
1 Rule
AlmaLinux OS 9 must implement DOD-approved encryption in the OpenSSL package.
Medium Severity
Without cryptographic integrity protections, information can be altered by unauthorized users without detection. Remote access (e.g., RDP) is access to DOD nonpublic information systems by an authorized user (or an information system) communicating through an external, nonorganization-controlled network. Remote access methods include, for example, dial-up, broadband, and wireless. Cryptographic mechanisms used for protecting the integrity of information include, for example, signed hash functions using asymmetric cryptography enabling distribution of the public key to verify the hash information while maintaining the confidentiality of the secret key used to generate the hash. The employed algorithms can be viewed in the /etc/crypto-policies/back-ends/openssl.config file.
SRG-OS-000250-GPOS-00093
1 Rule
AlmaLinux OS 9 must implement DOD-approved TLS encryption in the OpenSSL package.
Medium Severity
Without cryptographic integrity protections, information can be altered by unauthorized users without detection. Remote access (e.g., RDP) is access to DOD nonpublic information systems by an authorized user (or an information system) communicating through an external, nonorganization-controlled network. Remote access methods include, for example, dial-up, broadband, and wireless. Cryptographic mechanisms used for protecting the integrity of information include, for example, signed hash functions using asymmetric cryptography enabling distribution of the public key to verify the hash information while maintaining the confidentiality of the secret key used to generate the hash. The employed algorithms can be viewed in the /etc/crypto-policies/back-ends/openssl.config file.
SRG-OS-000033-GPOS-00014
1 Rule
AlmaLinux OS 9 must use the TuxCare FIPS repository.
High Severity
FIPS 140-3 validated packages are available from TuxCare. The TuxCare repositories provide the packages and updates not found in the community repositories. Satisfies: SRG-OS-000033-GPOS-00014, SRG-OS-000125-GPOS-00065, SRG-OS-000396-GPOS-00176, SRG-OS-000478-GPOS-00223
SRG-OS-000033-GPOS-00014
1 Rule
AlmaLinux OS 9 must use the TuxCare FIPS packages and not the default encryption packages.
High Severity
FIPS 140-3 validated packages are available from TuxCare. The original community packages must be replaced with the versions that have gone through the CMVP. Satisfies: SRG-OS-000033-GPOS-00014, SRG-OS-000478-GPOS-00223, SRG-OS-000396-GPOS-00176, SRG-OS-000125-GPOS-00065
SRG-OS-000033-GPOS-00014
1 Rule
AlmaLinux OS 9 must enable FIPS mode.
High Severity
Without confidentiality protection mechanisms, unauthorized individuals may gain access to sensitive information via a remote access session. Remote access is access to DOD nonpublic information systems by an authorized user (or an information system) communicating through an external, nonorganization-controlled network. Remote access methods include, for example, dial-up, broadband, and wireless. Encryption provides a means to secure the remote connection to prevent unauthorized access to the data traversing the remote access connection (e.g., RDP), thereby providing a degree of confidentiality. The encryption strength of a mechanism is selected based on the security categorization of the information. The operating system must use cryptographic modules that have been validated by NIST's FIPS 140-3 program. Using weak or untested cryptography could compromise the confidentiality and integrity of data at rest and in transit. Satisfies: SRG-OS-000033-GPOS-00014, SRG-OS-000478-GPOS-00223, SRG-OS-000396-GPOS-00176, SRG-OS-000125-GPOS-00065
SRG-OS-000002-GPOS-00002
1 Rule
AlmaLinux OS 9 must automatically expire temporary accounts within 72 hours.
Medium Severity
Temporary accounts are accounts created during a time of need when prompt action requires bypassing the normal account creation authorization process – such as during incident response. If these temporary accounts are left enabled (and may have elevated permissions via sudo, group membership or SSH keys) and are not automatically expired or manually removed, the security posture of the system will be degraded and left vulnerable to insider threat. Temporary accounts are not the same as "last resort" or "break glass" emergency accounts which are local system accounts to be used by and maintained by authorized system administrators when standard remote access/authentication is unavailable. Emergency accounts are not subject to removal or expiration requirements. Satisfies: SRG-OS-000002-GPOS-00002, SRG-OS-000123-GPOS-00064
SRG-OS-000004-GPOS-00004
1 Rule
AlmaLinux OS 9 must generate audit records for all account creations, modifications, disabling, and termination events that affect /etc/sudoers.
Medium Severity
Audit records provide a means to investigate events related to a security incident. Insufficient audit coverage will make identifying those responsible challenging or impossible. This auditd policy will watch for and alert the system administrators regarding any modifications to the "/etc/sudoers" file such as adding privileged users, groups, or commands. Satisfies: SRG-OS-000004-GPOS-00004, SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000304-GPOS-00121, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000470-GPOS-00214, SRG-OS-000471-GPOS-00215, SRG-OS-000239-GPOS-00089, SRG-OS-000240-GPOS-00090, SRG-OS-000241-GPOS-00091, SRG-OS-000303-GPOS-00120, SRG-OS-000466-GPOS-00210, SRG-OS-000476-GPOS-00221, SRG-OS-000755-GPOS-00220
SRG-OS-000004-GPOS-00004
1 Rule
AlmaLinux OS 9 must generate audit records for all account creations, modifications, disabling, and termination events that affect /etc/group.
Medium Severity
Audit records provide a means to investigate events related to a security incident. Insufficient audit coverage will make identifying those responsible challenging or impossible. This auditd policy will watch for and alert the system administrators regarding any modifications to the "/etc/group" file such as adding/removing/disabling groups. Satisfies: SRG-OS-000004-GPOS-00004, SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000304-GPOS-00121, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000470-GPOS-00214, SRG-OS-000471-GPOS-00215, SRG-OS-000239-GPOS-00089, SRG-OS-000240-GPOS-00090, SRG-OS-000241-GPOS-00091, SRG-OS-000303-GPOS-00120, SRG-OS-000466-GPOS-00210, SRG-OS-000476-GPOS-00221
SRG-OS-000004-GPOS-00004
1 Rule
AlmaLinux OS 9 must generate audit records for all account creations, modifications, disabling, and termination events that affect /etc/gshadow.
Medium Severity
Audit records provide a means to investigate events related to a security incident. Insufficient audit coverage will make identifying those responsible challenging or impossible. This auditd policy will watch for and alert the system administrators regarding any modifications to the "/etc/gshadow" file such as adding/removing/disabling users. Satisfies: SRG-OS-000004-GPOS-00004, SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000304-GPOS-00121, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000470-GPOS-00214, SRG-OS-000471-GPOS-00215, SRG-OS-000239-GPOS-00089, SRG-OS-000240-GPOS-00090, SRG-OS-000241-GPOS-00091, SRG-OS-000303-GPOS-00120, SRG-OS-000466-GPOS-00210, SRG-OS-000476-GPOS-00221
SRG-OS-000004-GPOS-00004
1 Rule
AlmaLinux OS 9 must generate audit records for all account creations, modifications, disabling, and termination events that affect /etc/security/opasswd.
Medium Severity
Audit records provide a means to investigate events related to a security incident. Insufficient audit coverage will make identifying those responsible challenging or impossible. This auditd policy will watch for and alert the system administrators regarding any modifications to the "/etc/security/opasswd" file such as adding/removing/disabling users. Satisfies: SRG-OS-000004-GPOS-00004, SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000304-GPOS-00121, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000470-GPOS-00214, SRG-OS-000471-GPOS-00215, SRG-OS-000239-GPOS-00089, SRG-OS-000240-GPOS-00090, SRG-OS-000241-GPOS-00091, SRG-OS-000303-GPOS-00120, SRG-OS-000466-GPOS-00210, SRG-OS-000476-GPOS-00221
SRG-OS-000004-GPOS-00004
1 Rule
AlmaLinux OS 9 must generate audit records for all account creations, modifications, disabling, and termination events that affect /etc/passwd.
Medium Severity
Audit records provide a means to investigate events related to a security incident. Insufficient audit coverage will make identifying those responsible challenging or impossible. This auditd policy will watch for and alert the system administrators regarding any modifications to the "/etc/passwd" file such as adding/removing/disabling users. Satisfies: SRG-OS-000004-GPOS-00004, SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000304-GPOS-00121, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000470-GPOS-00214, SRG-OS-000471-GPOS-00215, SRG-OS-000239-GPOS-00089, SRG-OS-000240-GPOS-00090, SRG-OS-000241-GPOS-00091, SRG-OS-000303-GPOS-00120, SRG-OS-000466-GPOS-00210, SRG-OS-000476-GPOS-00221, SRG-OS-000274-GPOS-00104, SRG-OS-000275-GPOS-00105, SRG-OS-000276-GPOS-00106, SRG-OS-000277-GPOS-00107
SRG-OS-000004-GPOS-00004
1 Rule
AlmaLinux OS 9 must generate audit records for all account creations, modifications, disabling, and termination events that affect /etc/shadow.
Medium Severity
Audit records provide a means to investigate events related to a security incident. Insufficient audit coverage will make identifying those responsible challenging or impossible. This auditd policy will watch for and alert the system administrators regarding any modifications to the "/etc/shadow" file such as adding/removing/disabling users. Satisfies: SRG-OS-000004-GPOS-00004, SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000304-GPOS-00121, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000470-GPOS-00214, SRG-OS-000471-GPOS-00215, SRG-OS-000239-GPOS-00089, SRG-OS-000240-GPOS-00090, SRG-OS-000241-GPOS-00091, SRG-OS-000303-GPOS-00120, SRG-OS-000466-GPOS-00210, SRG-OS-000476-GPOS-00221
SRG-OS-000004-GPOS-00004
1 Rule
AlmaLinux OS 9 must generate audit records for all account creations, modifications, disabling, and termination events that affect the files within /etc/sudoers.d/
Medium Severity
Audit records provide a means to investigate events related to a security incident. Insufficient audit coverage will make identifying those responsible challenging or impossible. This auditd policy will watch for and alert the system administrators regarding any modifications to the files within "/etc/sudoers.d/" such as adding privileged users, groups, or commands. Satisfies: SRG-OS-000004-GPOS-00004, SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000304-GPOS-00121, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000470-GPOS-00214, SRG-OS-000471-GPOS-00215, SRG-OS-000239-GPOS-00089, SRG-OS-000240-GPOS-00090, SRG-OS-000241-GPOS-00091, SRG-OS-000303-GPOS-00120, SRG-OS-000466-GPOS-00210, SRG-OS-000476-GPOS-00221
SRG-OS-000080-GPOS-00048
1 Rule
AlmaLinux OS 9 must require authentication to access emergency mode.
Medium Severity
This requirement prevents attackers with physical access from easily bypassing security on the machine and gaining root access. Such accesses are further prevented by configuring the bootloader password.
SRG-OS-000080-GPOS-00048
1 Rule
AlmaLinux OS 9 must require a boot loader password.
Medium Severity
Password protection on the boot loader configuration ensures users with physical access cannot trivially alter important bootloader settings. These include which kernel to use, and whether to enter single-user mode.
SRG-OS-000080-GPOS-00048
1 Rule
AlmaLinux OS 9 must require a unique superuser's name upon booting into single-user and maintenance modes.
Medium Severity
Having a nondefault grub superuser username makes password-guessing attacks less effective.
SRG-OS-000080-GPOS-00048
1 Rule
AlmaLinux OS 9 must require authentication to access single-user mode.
Medium Severity
This requirement prevents attackers with physical access from easily bypassing security on the machine and gaining root access. Such accesses are further prevented by configuring the bootloader password.
SRG-OS-000324-GPOS-00125
1 Rule
The systemd Ctrl-Alt-Delete burst key sequence in AlmaLinux OS 9 must be disabled.
High Severity
A locally logged-on user who presses Ctrl-Alt-Delete in quick succession when at the console can reboot the system. If accidentally pressed, as could happen in the case of a mixed OS environment, this can create the risk of short-term loss of availability of systems due to unintentional reboot. In a graphical user environment, risk of unintentional reboot from the Ctrl-Alt-Delete sequence is reduced because the user will be prompted before any action is taken.
SRG-OS-000324-GPOS-00125
1 Rule
The Ctrl-Alt-Delete key sequence must be disabled on AlmaLinux OS 9.
High Severity
A locally logged-on user who presses Ctrl-Alt-Delete when at the console can reboot the system. If accidentally pressed, as could happen in the case of a mixed OS environment, this can create the risk of short-term loss of availability of systems due to unintentional reboot. In a graphical user environment, risk of unintentional reboot from the Ctrl-Alt-Delete sequence is reduced because the user will be prompted before any action is taken.
SRG-OS-000324-GPOS-00125
1 Rule
AlmaLinux OS 9 must have the sudo package installed.
Medium Severity
"sudo" is a program designed to allow a system administrator to give limited root privileges to users and log root activity. The basic philosophy is to give as few privileges as possible but still allow system users to complete their work.
SRG-OS-000324-GPOS-00125
1 Rule
The AlmaLinux OS 9 debug-shell systemd service must be disabled.
Medium Severity
The debug-shell requires no authentication and provides root privileges to anyone who has physical access to the machine. While this feature is disabled by default, masking it adds an additional layer of assurance that it will not be enabled via a dependency in systemd. This also prevents attackers with physical access from easily bypassing security on the machine through valid troubleshooting configurations and gaining root access when the system is rebooted.
SRG-OS-000324-GPOS-00125
1 Rule
AlmaLinux OS 9 must enable kernel parameters to enforce discretionary access control on hardlinks.
Medium Severity
By enabling the fs.protected_hardlinks kernel parameter, users can no longer create soft or hard links to files they do not own. Disallowing such hardlinks mitigates vulnerabilities based on unsecure file systems accessed by privileged programs, avoiding an exploitation vector exploiting unsafe use of open() or creat().
SRG-OS-000324-GPOS-00125
1 Rule
AlmaLinux OS 9 must enable kernel parameters to enforce discretionary access control (DAC) on symlinks.
Medium Severity
By enabling the fs.protected_symlinks kernel parameter, symbolic links are permitted to be followed only when outside a sticky world-writable directory, or when the user identifier (UID) of the link and follower match, or when the directory owner matches the symlink's owner. Disallowing such symlinks helps mitigate vulnerabilities based on unsecure file systems accessed by privileged programs, avoiding an exploitation vector exploiting unsafe use of open() or creat().
SRG-OS-000327-GPOS-00127
1 Rule
AlmaLinux OS 9 must audit uses of the "execve" system call.
Medium Severity
Misuse of privileged functions, either intentionally or unintentionally by authorized users, or by unauthorized external entities that have compromised information system accounts, is a serious and ongoing concern and can have significant adverse impacts on organizations. Auditing the use of privileged functions is one way to detect such misuse and identify the risk from insider threats and the advanced persistent threat. Satisfies: SRG-OS-000327-GPOS-00127, SRG-OS-000326-GPOS-00126
SRG-OS-000021-GPOS-00005
1 Rule
AlmaLinux OS 9 must automatically lock an account when three unsuccessful logon attempts occur.
Medium Severity
By limiting the number of failed logon attempts, the risk of unauthorized system access via user password guessing, otherwise known as brute-force attacks, is reduced. Limits are imposed by locking the account.
SRG-OS-000021-GPOS-00005
1 Rule
AlmaLinux OS 9 must automatically lock the root account until the root account is released by an administrator when three unsuccessful logon attempts occur during a 15-minute time period.
Medium Severity
By limiting the number of failed logon attempts, the risk of unauthorized system access via user password guessing, otherwise known as brute-force attacks, is reduced. Limits are imposed by locking the account.
SRG-OS-000021-GPOS-00005
1 Rule
AlmaLinux OS 9 must automatically lock an account when three unsuccessful logon attempts occur during a 15-minute time period.
Medium Severity
By limiting the number of failed logon attempts, the risk of unauthorized system access via user password guessing, otherwise known as brute-force attacks, is reduced. Limits are imposed by locking the account.
SRG-OS-000021-GPOS-00005
1 Rule
AlmaLinux OS 9 must configure the use of the pam_faillock.so module in the /etc/pam.d/system-auth file.
Medium Severity
By limiting the number of failed logon attempts, the risk of unauthorized system access via user password guessing, otherwise known as brute-force attacks, is reduced. Limits are imposed by locking the account. If the pam_faillock.so module is not loaded, the system will not correctly lockout accounts to prevent password guessing attacks.
SRG-OS-000021-GPOS-00005
1 Rule
AlmaLinux OS 9 must configure the use of the pam_faillock.so module in the /etc/pam.d/password-auth file.
Medium Severity
By limiting the number of failed logon attempts, the risk of unauthorized system access via user password guessing, otherwise known as brute-force attacks, is reduced. Limits are imposed by locking the account. If the pam_faillock.so module is not loaded, the system will not correctly lockout accounts to prevent password guessing attacks.
SRG-OS-000021-GPOS-00005
1 Rule
AlmaLinux OS 9 must log username information when unsuccessful logon attempts occur.
Medium Severity
Without auditing of these events, it may be harder or impossible to identify what an attacker did after an attack. Satisfies: SRG-OS-000021-GPOS-00005, SRG-OS-000470-GPOS-00214
SRG-OS-000329-GPOS-00128
1 Rule
AlmaLinux OS 9 must maintain an account lock until the locked account is manually released by an administrator; and not automatically after a set time.
Medium Severity
By limiting the number of failed logon attempts, the risk of unauthorized system access via user password guessing, otherwise known as brute-force attacks, is reduced. Limits are imposed by locking the account.
SRG-OS-000329-GPOS-00128
1 Rule
AlmaLinux OS 9 must ensure account locks persist across reboots.
Medium Severity
By limiting the number of failed logon attempts, the risk of unauthorized system access via user password guessing, otherwise known as brute-forcing, is reduced. Limits are imposed by locking the account. Having account locks persist across reboots ensures that a locked account is only unlocked by an administrator. If the locks did not persist across reboots, an attacker could reboot the system to continue brute force attacks against the accounts on the system. The default /var/run/faillock directory is cleared upon reboot and should not be used.
SRG-OS-000329-GPOS-00128
1 Rule
AlmaLinux OS 9 must configure the appropriate SELinux context on the nondefault faillock tally directory.
Medium Severity
By limiting the number of failed logon attempts, the risk of unauthorized system access via user password guessing, otherwise known as brute-forcing, is reduced. Limits are imposed by locking the account. Not having the correct SELinux context on the faillock directory may lead to unauthorized access to the directory meaning that accounts could be unlocked by a nonadministrator.
SRG-OS-000023-GPOS-00006
1 Rule
AlmaLinux OS 9 must prevent users from disabling the Standard Mandatory DOD Notice and Consent Banner for graphical user interfaces.
Medium Severity
Display of a standardized and approved use notification before granting access to the operating system ensures privacy and security notification verbiage used is consistent with applicable federal laws, Executive Orders, directives, policies, regulations, standards, and guidance. System use notifications are required only for access via logon interfaces with human users and are not required when such human interfaces do not exist. The banner must be formatted in accordance with applicable DOD policy. Use the following verbiage for operating systems that can accommodate banners of 1300 characters: "You are accessing a U.S. Government (USG) Information System (IS) that is provided for USG-authorized use only. By using this IS (which includes any device attached to this IS), you consent to the following conditions: -The USG routinely intercepts and monitors communications on this IS for purposes including, but not limited to, penetration testing, COMSEC monitoring, network operations and defense, personnel misconduct (PM), law enforcement (LE), and counterintelligence (CI) investigations. -At any time, the USG may inspect and seize data stored on this IS. -Communications using, or data stored on, this IS are not private, are subject to routine monitoring, interception, and search, and may be disclosed or used for any USG-authorized purpose. -This IS includes security measures (e.g., authentication and access controls) to protect USG interests--not for your personal benefit or privacy. -Notwithstanding the above, using this IS does not constitute consent to PM, LE or CI investigative searching or monitoring of the content of privileged communications, or work product, related to personal representation or services by attorneys, psychotherapists, or clergy, and their assistants. Such communications and work product are private and confidential. See User Agreement for details." Use the following verbiage for operating systems that have severe limitations on the number of characters that can be displayed in the banner: "I've read & consent to terms in IS user agreem't." If a login banner is not displayed, it may be difficult to prosecute an attacker. Satisfies: SRG-OS-000023-GPOS-00006, SRG-OS-000228-GPOS-00088
SRG-OS-000023-GPOS-00006
1 Rule
AlmaLinux OS 9 must display the Standard Mandatory DOD Notice and Consent Banner before granting local or remote access to the system via a graphical user logon.
Medium Severity
Display of a standardized and approved use notification before granting access to the operating system ensures privacy and security notification verbiage used is consistent with applicable federal laws, Executive Orders, directives, policies, regulations, standards, and guidance. System use notifications are required only for access via logon interfaces with human users and are not required when such human interfaces do not exist. The banner must be formatted in accordance with applicable DOD policy. Use the following verbiage for operating systems that can accommodate banners of 1300 characters: "You are accessing a U.S. Government (USG) Information System (IS) that is provided for USG-authorized use only. By using this IS (which includes any device attached to this IS), you consent to the following conditions: -The USG routinely intercepts and monitors communications on this IS for purposes including, but not limited to, penetration testing, COMSEC monitoring, network operations and defense, personnel misconduct (PM), law enforcement (LE), and counterintelligence (CI) investigations. -At any time, the USG may inspect and seize data stored on this IS. -Communications using, or data stored on, this IS are not private, are subject to routine monitoring, interception, and search, and may be disclosed or used for any USG-authorized purpose. -This IS includes security measures (e.g., authentication and access controls) to protect USG interests--not for your personal benefit or privacy. -Notwithstanding the above, using this IS does not constitute consent to PM, LE or CI investigative searching or monitoring of the content of privileged communications, or work product, related to personal representation or services by attorneys, psychotherapists, or clergy, and their assistants. Such communications and work product are private and confidential. See User Agreement for details." Use the following verbiage for operating systems that have severe limitations on the number of characters that can be displayed in the banner: "I've read & consent to terms in IS user agreem't." If a login banner is not displayed, it may be difficult to prosecute an attacker. Satisfies: SRG-OS-000023-GPOS-00006, SRG-OS-000228-GPOS-00088
SRG-OS-000023-GPOS-00006
1 Rule
AlmaLinux OS 9 must display the Standard Mandatory DOD Notice and Consent Banner before granting local or remote access to the system via a command line user logon.
Medium Severity
Display of a standardized and approved use notification before granting access to the operating system ensures privacy and security notification verbiage used is consistent with applicable federal laws, Executive Orders, directives, policies, regulations, standards, and guidance. System use notifications are required only for access via logon interfaces with human users and are not required when such human interfaces do not exist. The banner must be formatted in accordance with applicable DOD policy. Use the following verbiage for operating systems that can accommodate banners of 1300 characters: "You are accessing a U.S. Government (USG) Information System (IS) that is provided for USG-authorized use only. By using this IS (which includes any device attached to this IS), you consent to the following conditions: -The USG routinely intercepts and monitors communications on this IS for purposes including, but not limited to, penetration testing, COMSEC monitoring, network operations and defense, personnel misconduct (PM), law enforcement (LE), and counterintelligence (CI) investigations. -At any time, the USG may inspect and seize data stored on this IS. -Communications using, or data stored on, this IS are not private, are subject to routine monitoring, interception, and search, and may be disclosed or used for any USG-authorized purpose. -This IS includes security measures (e.g., authentication and access controls) to protect USG interests--not for your personal benefit or privacy. -Notwithstanding the above, using this IS does not constitute consent to PM, LE or CI investigative searching or monitoring of the content of privileged communications, or work product, related to personal representation or services by attorneys, psychotherapists, or clergy, and their assistants. Such communications and work product are private and confidential. See User Agreement for details." Use the following verbiage for operating systems that have severe limitations on the number of characters that can be displayed in the banner: "I've read & consent to terms in IS user agreem't." If a login banner is not displayed, it may be difficult to prosecute an attacker. Satisfies: SRG-OS-000023-GPOS-00006, SRG-OS-000228-GPOS-00088
SRG-OS-000023-GPOS-00006
1 Rule
AlmaLinux OS 9 must display the Standard Mandatory DOD Notice and Consent Banner before granting local or remote access to the system via an SSH user logon.
Medium Severity
Display of a standardized and approved use notification before granting access to the operating system ensures privacy and security notification verbiage used is consistent with applicable federal laws, Executive Orders, directives, policies, regulations, standards, and guidance. System use notifications are required only for access via logon interfaces with human users and are not required when such human interfaces do not exist. The banner must be formatted in accordance with applicable DOD policy. Use the following verbiage for operating systems that can accommodate banners of 1300 characters: "You are accessing a U.S. Government (USG) Information System (IS) that is provided for USG-authorized use only. By using this IS (which includes any device attached to this IS), you consent to the following conditions: -The USG routinely intercepts and monitors communications on this IS for purposes including, but not limited to, penetration testing, COMSEC monitoring, network operations and defense, personnel misconduct (PM), law enforcement (LE), and counterintelligence (CI) investigations. -At any time, the USG may inspect and seize data stored on this IS. -Communications using, or data stored on, this IS are not private, are subject to routine monitoring, interception, and search, and may be disclosed or used for any USG-authorized purpose. -This IS includes security measures (e.g., authentication and access controls) to protect USG interests--not for your personal benefit or privacy. -Notwithstanding the above, using this IS does not constitute consent to PM, LE or CI investigative searching or monitoring of the content of privileged communications, or work product, related to personal representation or services by attorneys, psychotherapists, or clergy, and their assistants. Such communications and work product are private and confidential. See User Agreement for details." Use the following verbiage for operating systems that have severe limitations on the number of characters that can be displayed in the banner: "I've read & consent to terms in IS user agreem't." If a login banner is not displayed, it may be difficult to prosecute an attacker. Satisfies: SRG-OS-000023-GPOS-00006, SRG-OS-000228-GPOS-00088
SRG-OS-000363-GPOS-00150
1 Rule
AlmaLinux OS 9 must have the s-nail package installed.
Medium Severity
The "s-nail" package provides the mail command required to allow sending email notifications of unauthorized configuration changes to designated personnel.
SRG-OS-000364-GPOS-00151
1 Rule
AlmaLinux OS 9 SSH daemon must not allow Generic Security Service Application Program Interface (GSSAPI) authentication.
Medium Severity
GSSAPI authentication is used to provide additional authentication mechanisms to applications. Allowing GSSAPI authentication through SSH exposes the system's GSSAPI to remote hosts, increasing the attack surface of the system.
SRG-OS-000364-GPOS-00151
1 Rule
AlmaLinux OS 9 SSH daemon must not allow Kerberos authentication.
Medium Severity
Kerberos authentication for SSH is often implemented using Generic Security Service Application Program Interface (GSSAPI). If Kerberos is enabled through SSH, the SSH daemon provides a means of access to the system's Kerberos implementation. Vulnerabilities in the system's Kerberos implementations may be subject to exploitation.
SRG-OS-000366-GPOS-00153
1 Rule
AlmaLinux OS 9 must check the GPG signature of software packages originating from external software repositories before installation.
High Severity
Changes to any software components can have significant effects on the overall security of the operating system. This requirement ensures the software has not been tampered with and that it has been provided by a trusted vendor. Accordingly, patches, service packs, device drivers, or operating system components must be signed with a certificate recognized and approved by the organization. Verifying the authenticity of the software prior to installation validates the integrity of the patch or upgrade received from a vendor. This ensures the software has not been tampered with and that it has been provided by a trusted vendor. Self-signed certificates are not allowed by this requirement. The operating system should not have to verify the software again. This requirement does not mandate DOD certificates for this purpose; however, the certificate used to verify the software must be from an approved certificate authority (CA).
SRG-OS-000366-GPOS-00153
1 Rule
AlmaLinux OS 9 must ensure cryptographic verification of vendor software packages.
High Severity
Changes to any software components can have significant effects on the overall security of the operating system. This requirement ensures the software has not been tampered with and that it has been provided by a trusted vendor. Accordingly, patches, service packs, device drivers, or operating system components must be signed with a certificate recognized and approved by the organization. Verifying the authenticity of the software prior to installation validates the integrity of the patch or upgrade received from a vendor. This ensures the software has not been tampered with and that it has been provided by a trusted vendor. Self-signed certificates are not allowed by this requirement. The operating system should not have to verify the software again. This requirement does not mandate DOD certificates for this purpose; however, the certificate used to verify the software must be from an approved certificate authority (CA).
SRG-OS-000366-GPOS-00153
1 Rule
AlmaLinux OS 9 must check the GPG signature of locally installed software packages before installation.
High Severity
Changes to any software components can have significant effects on the overall security of the operating system. This requirement ensures the software has not been tampered with and that it has been provided by a trusted vendor. Accordingly, patches, service packs, device drivers, or operating system components must be signed with a certificate recognized and approved by the organization. Verifying the authenticity of the software prior to installation validates the integrity of the patch or upgrade received from a vendor. This ensures the software has not been tampered with and that it has been provided by a trusted vendor. Self-signed certificates are disallowed by this requirement. The operating system should not have to verify the software again. This requirement does not mandate DOD certificates for this purpose; however, the certificate used to verify the software must be from an approved certificate authority (CA).
SRG-OS-000366-GPOS-00153
1 Rule
AlmaLinux OS 9 must check the GPG signature of repository metadata before package installation.
High Severity
Changes to any software components can have significant effects on the overall security of the operating system. This requirement ensures the software has not been tampered with and that it has been provided by a trusted vendor. Accordingly, patches, service packs, device drivers, or operating system components must be signed with a certificate recognized and approved by the organization. Verifying the authenticity of the software prior to installation validates the integrity of the patch or upgrade received from a vendor. This ensures the software has not been tampered with and that it has been provided by a trusted vendor. Self-signed certificates are disallowed by this requirement. The operating system should not have to verify the software again. This requirement does not mandate DOD certificates for this purpose; however, the certificate used to verify the software must be from an approved certificate authority (CA).
SRG-OS-000366-GPOS-00153
1 Rule
AlmaLinux OS 9 must have GPG signature verification enabled for all software repositories.
High Severity
Changes to any software components can have significant effects on the overall security of the operating system. This requirement ensures the software has not been tampered with and that it has been provided by a trusted vendor. Accordingly, patches, service packs, device drivers, or operating system components must be signed with a certificate recognized and approved by the organization. Verifying the authenticity of the software prior to installation validates the integrity of the patch or upgrade received from a vendor. This ensures the software has not been tampered with and that it has been provided by a trusted vendor. Self-signed certificates are disallowed by this requirement. The operating system should not have to verify the software again. This requirement does not mandate DOD certificates for this purpose; however, the certificate used to verify the software must be from an approved certificate authority (CA).
SRG-OS-000366-GPOS-00153
1 Rule
AlmaLinux OS 9 must prevent the loading of a new kernel for later execution.
Medium Severity
Changes to any software components can have significant effects on the overall security of the operating system. This requirement ensures the software has not been tampered with and that it has been provided by a trusted vendor. Disabling kexec_load prevents an unsigned kernel image (that could be a windows kernel or modified vulnerable kernel) from being loaded. Kexec can be used subvert the entire secureboot process and should be avoided at all costs especially since it can load unsigned kernel images.
SRG-OS-000259-GPOS-00100
1 Rule
AlmaLinux OS 9 system commands must be group-owned by root or a system account.
Medium Severity
If AlmaLinux OS 9 allowed any user to make changes to software libraries, then those changes might be implemented without undergoing the appropriate testing and approvals that are part of a robust change management process. This requirement applies to AlmaLinux OS 9 with software libraries that are accessible and configurable, as in the case of interpreted languages. Software libraries also include privileged programs that execute with escalated privileges.
SRG-OS-000259-GPOS-00100
1 Rule
AlmaLinux OS 9 system commands must be owned by root.
Medium Severity
If AlmaLinux OS 9 allowed any user to make changes to software libraries, then those changes might be implemented without undergoing the appropriate testing and approvals that are part of a robust change management process. This requirement applies to AlmaLinux OS 9 with software libraries that are accessible and configurable, as in the case of interpreted languages. Software libraries also include privileged programs that execute with escalated privileges.
SRG-OS-000259-GPOS-00100
1 Rule
AlmaLinux OS 9 system commands must have mode 755 or less permissive.
Medium Severity
If AlmaLinux OS 9 allowed any user to make changes to software libraries, then those changes might be implemented without undergoing the appropriate testing and approvals that are part of a robust change management process. This requirement applies to AlmaLinux OS 9 with software libraries that are accessible and configurable, as in the case of interpreted languages. Software libraries also include privileged programs that execute with escalated privileges.
SRG-OS-000259-GPOS-00100
1 Rule
AlmaLinux OS 9 library directories must be group-owned by root or a system account.
Medium Severity
If AlmaLinux OS 9 allowed any user to make changes to software libraries, then those changes might be implemented without undergoing the appropriate testing and approvals that are part of a robust change management process. This requirement applies to AlmaLinux OS 9 with software libraries that are accessible and configurable, as in the case of interpreted languages. Software libraries also include privileged programs that execute with escalated privileges.
SRG-OS-000259-GPOS-00100
1 Rule
AlmaLinux OS 9 library directories must be owned by root.
Medium Severity
If AlmaLinux OS 9 allowed any user to make changes to software libraries, then those changes might be implemented without undergoing the appropriate testing and approvals that are part of a robust change management process. This requirement applies to AlmaLinux OS 9 with software libraries that are accessible and configurable, as in the case of interpreted languages. Software libraries also include privileged programs that execute with escalated privileges.
SRG-OS-000259-GPOS-00100
1 Rule
AlmaLinux OS 9 library directories must have mode 755 or less permissive.
Medium Severity
If AlmaLinux OS 9 allowed any user to make changes to software libraries, then those changes might be implemented without undergoing the appropriate testing and approvals that are part of a robust change management process. This requirement applies to AlmaLinux OS 9 with software libraries that are accessible and configurable, as in the case of interpreted languages. Software libraries also include privileged programs that execute with escalated privileges.
SRG-OS-000259-GPOS-00100
1 Rule
AlmaLinux OS 9 library files must be group-owned by root or a system account.
Medium Severity
If AlmaLinux OS 9 allowed any user to make changes to software libraries, then those changes might be implemented without undergoing the appropriate testing and approvals that are part of a robust change management process. This requirement applies to AlmaLinux OS 9 with software libraries that are accessible and configurable, as in the case of interpreted languages. Software libraries also include privileged programs that execute with escalated privileges.
SRG-OS-000259-GPOS-00100
1 Rule
AlmaLinux OS 9 library files must be owned by root.
Medium Severity
If AlmaLinux OS 9 allowed any user to make changes to software libraries, then those changes might be implemented without undergoing the appropriate testing and approvals that are part of a robust change management process. This requirement applies to AlmaLinux OS 9 with software libraries that are accessible and configurable, as in the case of interpreted languages. Software libraries also include privileged programs that execute with escalated privileges.
SRG-OS-000259-GPOS-00100
1 Rule
AlmaLinux OS 9 library files must have mode 755 or less permissive.
Medium Severity
If AlmaLinux OS 9 allowed any user to make changes to software libraries, then those changes might be implemented without undergoing the appropriate testing and approvals that are part of a robust change management process. This requirement applies to AlmaLinux OS 9 with software libraries that are accessible and configurable, as in the case of interpreted languages. Software libraries also include privileged programs that execute with escalated privileges.
SRG-OS-000480-GPOS-00227
1 Rule
AlmaLinux OS 9 must disable core dumps for all users.
Medium Severity
A core dump includes a memory image taken at the time the operating system terminates an application. The memory image could contain sensitive data and is generally useful only for developers or system operators trying to debug problems. Enabling core dumps on production systems is not recommended; however, there may be overriding operational requirements to enable advanced debugging. Permitting temporary enablement of core dumps during such situations must be reviewed through local needs and policy.
SRG-OS-000480-GPOS-00227
1 Rule
AlmaLinux OS 9 must disable acquiring, saving, and processing core dumps.
Medium Severity
A core dump includes a memory image taken at the time the operating system terminates an application. The memory image could contain sensitive data and is generally useful only for developers or system operators trying to debug problems. Enabling core dumps on production systems is not recommended; however, there may be overriding operational requirements to enable advanced debugging. Permitting temporary enablement of core dumps during such situations must be reviewed through local needs and policy.
SRG-OS-000480-GPOS-00227
1 Rule
AlmaLinux OS 9 must disable storing core dumps.
Medium Severity
A core dump includes a memory image taken at the time the operating system terminates an application. The memory image could contain sensitive data and is generally useful only for developers or system operators trying to debug problems. Enabling core dumps on production systems is not recommended; however, there may be overriding operational requirements to enable advanced debugging. Permitting temporary enablement of core dumps during such situations must be reviewed through local needs and policy.
SRG-OS-000480-GPOS-00227
1 Rule
AlmaLinux OS 9 must disable core dump backtraces.
Medium Severity
A core dump includes a memory image taken at the time the operating system terminates an application. The memory image could contain sensitive data and is generally useful only for developers or system operators trying to debug problems. Enabling core dumps on production systems is not recommended; however, there may be overriding operational requirements to enable advanced debugging. Permitting temporary enablement of core dumps during such situations must be reviewed through local needs and policy.
SRG-OS-000480-GPOS-00227
1 Rule
AlmaLinux OS 9 must disable the kernel.core_pattern.
Medium Severity
A core dump includes a memory image taken at the time the operating system terminates an application. The memory image could contain sensitive data and is generally useful only for developers trying to debug problems.
SRG-OS-000480-GPOS-00227
1 Rule
AlmaLinux OS 9 cron configuration files directory must be group-owned by root.
Medium Severity
Service configuration files enable or disable features of their respective services that if configured incorrectly can lead to insecure and vulnerable configurations; therefore, service configuration files must be owned by the correct group to prevent unauthorized changes.
SRG-OS-000480-GPOS-00227
1 Rule
AlmaLinux OS 9 cron configuration files directory must be owned by root.
Medium Severity
Service configuration files enable or disable features of their respective services that if configured incorrectly can lead to insecure and vulnerable configurations; therefore, service configuration files must be owned by the correct group to prevent unauthorized changes.
SRG-OS-000480-GPOS-00227
1 Rule
AlmaLinux OS 9 cron configuration directories must have a mode of 0700 or less permissive.
Medium Severity
Service configuration files enable or disable features of their respective services that if configured incorrectly can lead to insecure and vulnerable configurations. Therefore, service configuration files should have the correct access rights to prevent unauthorized changes.
SRG-OS-000480-GPOS-00227
1 Rule
AlmaLinux OS 9 /etc/crontab file must have mode 0600.
Medium Severity
Service configuration files enable or disable features of their respective services that if configured incorrectly can lead to insecure and vulnerable configurations; therefore, service configuration files must have the correct access rights to prevent unauthorized changes.
SRG-OS-000480-GPOS-00227
1 Rule
AlmaLinux OS 9 must disable the ability of a user to accidentally press Ctrl-Alt-Del and cause a system to shut down or reboot.
Medium Severity
A locally logged-in user who presses Ctrl-Alt-Del, when at the console, can reboot the system. If accidentally pressed, as could happen in the case of mixed OS environment, this can create the risk of short-term loss of availability of systems due to unintentional reboot.
SRG-OS-000480-GPOS-00227
1 Rule
AlmaLinux OS 9 must prevent a user from overriding the Ctrl-Alt-Del sequence settings for the graphical user interface.
Medium Severity
A locally logged-in user who presses Ctrl-Alt-Del, when at the console, can reboot the system. If accidentally pressed, as could happen in the case of mixed OS environment, this can create the risk of short-term loss of availability of systems due to unintentional reboot.
SRG-OS-000480-GPOS-00227
1 Rule
All AlmaLinux OS 9 local files and directories must have a valid group owner.
Medium Severity
Files without a valid group owner may be unintentionally inherited if a group is assigned the same Group Identifier (GID) as the GID of the files without a valid group owner.
SRG-OS-000480-GPOS-00227
1 Rule
All AlmaLinux OS 9 local files and directories must have a valid owner.
Medium Severity
Unowned files and directories may be unintentionally inherited if a user is assigned the same user identifier "UID" as the UID of the unowned files.
SRG-OS-000480-GPOS-00227
1 Rule
AlmaLinux OS 9 /etc/group- file must be group owned by root.
Medium Severity
The "/etc/group-" file is a backup file of "/etc/group", and as such, contains information regarding groups that are configured on the system. Protection of this file is important for system security.
SRG-OS-000480-GPOS-00227
1 Rule
AlmaLinux OS 9 /etc/group- file must be owned by root.
Medium Severity
The "/etc/group-" file is a backup file of "/etc/group", and as such, contains information regarding groups that are configured on the system. Protection of this file is important for system security.
SRG-OS-000480-GPOS-00227
1 Rule
AlmaLinux OS 9 /etc/group- file must have mode 0644 or less permissive to prevent unauthorized access.
Medium Severity
The "/etc/group-" file is a backup file of "/etc/group", and as such, contains information regarding groups that are configured on the system. Protection of this file is important for system security.
SRG-OS-000480-GPOS-00227
1 Rule
AlmaLinux OS 9 /etc/group file must be group owned by root.
Medium Severity
The "/etc/group" file contains information regarding groups that are configured on the system. Protection of this file is important for system security.
SRG-OS-000480-GPOS-00227
1 Rule
AlmaLinux OS 9 /etc/group file must be owned by root.
Medium Severity
The "/etc/group" file contains information regarding groups that are configured on the system. Protection of this file is important for system security.
SRG-OS-000480-GPOS-00227
1 Rule
AlmaLinux OS 9 /etc/group file must have mode 0644 or less permissive to prevent unauthorized access.
Medium Severity
The "/etc/group" file contains information regarding groups that are configured on the system. Protection of this file is important for system security.
SRG-OS-000480-GPOS-00227
1 Rule
The /boot/grub2/grub.cfg file must be group-owned by root.
Medium Severity
The "root" group is a highly privileged group. Furthermore, the group-owner of this file should not have any access privileges anyway.
SRG-OS-000480-GPOS-00227
1 Rule
The /boot/grub2/grub.cfg file must be owned by root.
Medium Severity
The "/boot/grub2/grub.cfg" file stores sensitive system configuration. Protection of this file is critical for system security.
SRG-OS-000480-GPOS-00227
1 Rule
AlmaLinux OS 9 must disable the ability of systemd to spawn an interactive boot process.
Medium Severity
Using interactive or recovery boot, the console user could disable auditing, firewalls, or other services, weakening system security.
SRG-OS-000480-GPOS-00227
1 Rule
AlmaLinux OS 9 /etc/gshadow- file must be group-owned by root.
Medium Severity
The "/etc/gshadow-" file is a backup of "/etc/gshadow", and as such, contains group password hashes. Protection of this file is critical for system security.
SRG-OS-000480-GPOS-00227
1 Rule
AlmaLinux OS 9 /etc/gshadow- file must be owned by root.
Medium Severity
The "/etc/gshadow-" file is a backup of "/etc/gshadow", and as such, contains group password hashes. Protection of this file is critical for system security.
SRG-OS-000480-GPOS-00227
1 Rule
AlmaLinux OS 9 /etc/gshadow- file must have mode 0000 or less permissive to prevent unauthorized access.
Medium Severity
The "/etc/gshadow-" file is a backup of "/etc/gshadow", and as such, contains group password hashes. Protection of this file is critical for system security.
SRG-OS-000480-GPOS-00227
1 Rule
AlmaLinux OS 9 /etc/gshadow file must be group-owned by root.
Medium Severity
The "/etc/gshadow" file contains group password hashes. Protection of this file is critical for system security.
SRG-OS-000480-GPOS-00227
1 Rule
AlmaLinux OS 9 /etc/gshadow file must be owned by root.
Medium Severity
The "/etc/gshadow" file contains group password hashes. Protection of this file is critical for system security.
SRG-OS-000480-GPOS-00227
1 Rule
AlmaLinux OS 9 /etc/gshadow file must have mode 0000 or less permissive to prevent unauthorized access.
Medium Severity
The "/etc/gshadow" file contains group password hashes. Protection of this file is critical for system security.
SRG-OS-000480-GPOS-00227
1 Rule
The graphical display manager must not be the default target on AlmaLinux OS 9 unless approved.
Medium Severity
Unnecessary service packages must not be installed to decrease the attack surface of the system. Graphical display managers have a long history of security vulnerabilities and must not be used, unless approved and documented.
SRG-OS-000480-GPOS-00227
1 Rule
AlmaLinux OS 9 must disable the user list at logon for graphical user interfaces.
Medium Severity
Leaving the user list enabled is a security risk since it allows anyone with physical access to the system to enumerate known user accounts without authenticated access to the system.
SRG-OS-000480-GPOS-00230
1 Rule
All AlmaLinux OS 9 local interactive user accounts must be assigned a home directory upon creation.
Medium Severity
If local interactive users are not assigned a valid home directory, there is no place for the storage and control of files they should own.
SRG-OS-000480-GPOS-00230
1 Rule
All AlmaLinux OS 9 local interactive user home directories defined in the /etc/passwd file must exist.
Medium Severity
If a local interactive user has a home directory defined that does not exist, the user may be given access to the / directory as the current working directory upon logon. This could create a denial of service because the user would not be able to access their logon configuration files, and it may give them visibility to system files they normally would not be able to access.
SRG-OS-000480-GPOS-00230
1 Rule
All AlmaLinux OS 9 local interactive user home directories must be group-owned by the home directory owner's primary group.
Medium Severity
If the Group Identifier (GID) of a local interactive users home directory is not the same as the primary GID of the user, this would allow unauthorized access to the users files, and users that share the same group may not be able to access files that they legitimately should.
SRG-OS-000480-GPOS-00230
1 Rule
AlmaLinux OS 9 must prevent code from being executed on file systems that contain user home directories.
Medium Severity
The "noexec" mount option causes the system to not execute binary files. This option must be used for mounting any file system not containing approved binary files, as they may be incompatible. Executing files from untrusted file systems increases the opportunity for nonprivileged users to attain unauthorized administrative access.
SRG-OS-000480-GPOS-00230
1 Rule
A separate file system must be used for user home directories (such as /home or an equivalent).
Medium Severity
Ensuring that "/home" is mounted on its own partition enables the setting of more restrictive mount options, and also helps ensure that users cannot trivially fill partitions used for log or audit data storage.
SRG-OS-000480-GPOS-00230
1 Rule
All AlmaLinux OS 9 local interactive users must have a home directory assigned in the /etc/passwd file.
Medium Severity
If local interactive users are not assigned a valid home directory, there is no place for the storage and control of files they should own.
SRG-OS-000480-GPOS-00230
1 Rule
Executable search paths within the initialization files of all local interactive AlmaLinux OS 9 users must only contain paths that resolve to the system default or the users home directory.
Medium Severity
The executable search path (typically the $PATH environment variable) contains a list of directories for the shell to search to find executables. If this path includes the current working directory (other than the users home directory), executables in these directories may be executed instead of system commands. This variable is formatted as a colon-separated list of directories. If there is an empty entry, such as a leading or trailing colon or two consecutive colons, this is interpreted as the current working directory. If deviations from the default system search path for the local interactive user are required, they must be documented with the information system security officer (ISSO).
SRG-OS-000480-GPOS-00230
1 Rule
All AlmaLinux OS 9 local interactive user home directories must have mode 0750 or less permissive.
Medium Severity
Excessive permissions on local interactive user home directories may allow unauthorized access to user files by other users.
SRG-OS-000480-GPOS-00229
1 Rule
AlmaLinux OS 9 must not allow unattended or automatic logon via the graphical user interface.
High Severity
Failure to restrict system access to authenticated users negatively impacts operating system security.
SRG-OS-000480-GPOS-00227
1 Rule
AlmaLinux OS 9 must enforce a delay of at least four seconds between logon prompts following a failed logon attempt.
Medium Severity
Increasing the time between a failed authentication attempt and prompting to re-enter credentials helps to slow a single-threaded brute force attack. Satisfies: SRG-OS-000480-GPOS-00227, SRG-OS-000480-GPOS-00226
SRG-OS-000480-GPOS-00227
1 Rule
AlmaLinux OS 9 must not allow blank or null passwords.
Medium Severity
If an account has an empty password, anyone could log in and run commands with the privileges of that account. Accounts with empty passwords should never be used in operational environments.
SRG-OS-000480-GPOS-00227
1 Rule
AlmaLinux OS 9 must not have accounts configured with blank or null passwords.
Medium Severity
If an account has an empty password, anyone could log in and run commands with the privileges of that account. Accounts with empty passwords should never be used in operational environments.
SRG-OS-000480-GPOS-00227
1 Rule
AlmaLinux OS 9 /etc/passwd- file must be group-owned by root.
Medium Severity
The "/etc/passwd-" file is a backup file of "/etc/passwd", and as such, contains information about the users that are configured on the system. Protection of this file is critical for system security.
SRG-OS-000480-GPOS-00227
1 Rule
AlmaLinux OS 9 /etc/passwd- file must be owned by root.
Medium Severity
The "/etc/passwd-" file is a backup file of "/etc/passwd", and as such, contains information about the users that are configured on the system. Protection of this file is critical for system security.
SRG-OS-000480-GPOS-00227
1 Rule
AlmaLinux OS 9 /etc/passwd- file must have mode 0644 or less permissive to prevent unauthorized access.
Medium Severity
The "/etc/passwd-" file is a backup file of "/etc/passwd", and as such, contains information about the users that are configured on the system. Protection of this file is critical for system security.
SRG-OS-000480-GPOS-00227
1 Rule
AlmaLinux OS 9 /etc/passwd file must be group-owned by root.
Medium Severity
The "/etc/passwd" file contains information about the users that are configured on the system. Protection of this file is critical for system security.
SRG-OS-000480-GPOS-00227
1 Rule
AlmaLinux OS 9 /etc/passwd file must be owned by root.
Medium Severity
The "/etc/passwd" file contains information about the users that are configured on the system. Protection of this file is critical for system security.
SRG-OS-000480-GPOS-00227
1 Rule
AlmaLinux OS 9 /etc/passwd file must have mode 0644 or less permissive to prevent unauthorized access.
Medium Severity
If the "/etc/passwd" file is writable by a group-owner or the world the risk of its compromise is increased. The file contains the list of accounts on the system and associated information, and protection of this file is critical for system security.
SRG-OS-000480-GPOS-00227
1 Rule
AlmaLinux OS 9 /etc/shadow- file must be group-owned by root.
Medium Severity
The "/etc/shadow-" file is a backup file of "/etc/shadow", and as such, contains the list of local system accounts and password hashes. Protection of this file is critical for system security.
SRG-OS-000480-GPOS-00227
1 Rule
AlmaLinux OS 9 /etc/shadow- file must be owned by root.
Medium Severity
The "/etc/shadow-" file is a backup file of "/etc/shadow", and as such, contains the list of local system accounts and password hashes. Protection of this file is critical for system security.
SRG-OS-000480-GPOS-00227
1 Rule
AlmaLinux OS 9 /etc/shadow- file must have mode 0000 or less permissive to prevent unauthorized access.
Medium Severity
The "/etc/shadow-" file is a backup file of "/etc/shadow", and as such, contains the list of local system accounts and password hashes. Protection of this file is critical for system security.
SRG-OS-000480-GPOS-00227
1 Rule
AlmaLinux OS 9 /etc/shadow file must be group-owned by root.
Medium Severity
The "/etc/shadow" file contains the list of local system accounts and stores password hashes. Protection of this file is critical for system security. Failure to give ownership of this file to root provides the designated owner with access to sensitive information, which could weaken the system security posture.
SRG-OS-000480-GPOS-00227
1 Rule
AlmaLinux OS 9 /etc/shadow file must be owned by root.
Medium Severity
The "/etc/shadow" file contains the list of local system accounts and stores password hashes. Protection of this file is critical for system security. Failure to give ownership of this file to root provides the designated owner with access to sensitive information, which could weaken the system security posture.
SRG-OS-000480-GPOS-00227
1 Rule
AlmaLinux OS 9 /etc/shadow file must have mode 0000 to prevent unauthorized access.
Medium Severity
The "/etc/shadow" file contains the list of local system accounts and stores password hashes. Protection of this file is critical for system security. Failure to give ownership of this file to root provides the designated owner with access to sensitive information, which could weaken the system security posture.
SRG-OS-000480-GPOS-00227
1 Rule
AlmaLinux OS 9 must restrict privilege elevation to authorized personnel.
Medium Severity
If the "sudoers" file is not configured correctly, any user defined on the system can initiate privileged actions on the target system.
SRG-OS-000480-GPOS-00227
1 Rule
AlmaLinux OS 9 must use the invoking user's password for privilege escalation when using "sudo".
Medium Severity
If the rootpw, targetpw, or runaspw flags are defined and not disabled, by default the operating system will prompt the invoking user for the "root" user password.
SRG-OS-000480-GPOS-00228
1 Rule
AlmaLinux OS 9 must set the umask value to 077 for all local interactive user accounts.
Medium Severity
Setting the most restrictive default permissions ensures that when new accounts are created they do not have unnecessary access. With a UMASK of 077, files will be created with 0600 permissions (owner read/write only) and directories will have 0700 permissions (owner read/write/execute only).
SRG-OS-000480-GPOS-00228
1 Rule
AlmaLinux OS 9 must define default permissions for all authenticated users in such a way that the user can only read and modify their own files.
Medium Severity
Setting the most restrictive default permissions ensures that when new accounts are created they do not have unnecessary access. With a UMASK of 077, files will be created with 0600 permissions (owner read/write only) and directories will have 0700 permissions (owner read/write/execute only).
SRG-OS-000480-GPOS-00228
1 Rule
AlmaLinux OS 9 must define default permissions for PAM users.
Medium Severity
Setting the most restrictive default permissions ensures that when new accounts are created they do not have unnecessary access. With a UMASK of 077, files will be created with 0600 permissions (owner read/write only) and directories will have 0700 permissions (owner read/write/execute only).
SRG-OS-000480-GPOS-00228
1 Rule
AlmaLinux OS 9 must define default permissions for logon and nonlogon shells.
Medium Severity
Setting the most restrictive default permissions ensures that when new accounts are created they do not have unnecessary access. With a UMASK of 077, files will be created with 0600 permissions (owner read/write only) and directories will have 0700 permissions (owner read/write/execute only).
SRG-OS-000480-GPOS-00227
1 Rule
AlmaLinux OS 9 must not have unauthorized accounts.
Medium Severity
Accounts providing no operational purpose provide additional opportunities for system compromise. Unnecessary accounts include user accounts for individuals not requiring access to the system and application accounts for applications not installed on the system.
SRG-OS-000480-GPOS-00227
1 Rule
AlmaLinux OS 9 must be configured so that the file integrity tool verifies Access Control Lists (ACLs).
Medium Severity
ACLs can provide permissions beyond those permitted through the file mode and must be verified by the file integrity tools.
SRG-OS-000480-GPOS-00227
1 Rule
AlmaLinux OS 9 must use a file integrity tool that is configured to use FIPS 140-3-approved cryptographic hashes for validating file contents and directories.
Medium Severity
File integrity tools use cryptographic hashes for verifying file contents and directories have not been altered. These hashes must be FIPS 140-3 approved cryptographic hashes.
SRG-OS-000480-GPOS-00227
1 Rule
AlmaLinux OS 9 must be configured so that the file integrity tool verifies extended attributes.
Medium Severity
Extended attributes in file systems are used to contain arbitrary data and file metadata with security implications.
SRG-OS-000480-GPOS-00225
1 Rule
AlmaLinux OS 9 must prevent the use of dictionary words for passwords.
Medium Severity
Use of a complex password helps to increase the time and resources required to compromise the password. Password complexity, or strength, is a measure of the effectiveness of a password in resisting attempts at guessing and brute-force attacks. Password complexity is one factor of several that determines how long it takes to crack a password. The more complex the password, the greater the number of possible combinations that need to be tested before the password is compromised.
SRG-OS-000480-GPOS-00227
1 Rule
AlmaLinux OS 9 must not accept router advertisements on all IPv6 interfaces.
Medium Severity
An illicit router advertisement message could result in a man-in-the-middle attack.
SRG-OS-000480-GPOS-00227
1 Rule
AlmaLinux OS 9 must ignore Internet Control Message Protocol (ICMP) redirect messages.
Medium Severity
ICMP redirect messages are used by routers to inform hosts that a more direct route exists for a particular destination. These messages modify the host's route table and are unauthenticated. An illicit ICMP redirect message could result in a man-in-the-middle attack. This feature of the IP protocol has few legitimate uses. It should be disabled unless absolutely required.
SRG-OS-000480-GPOS-00232
1 Rule
The firewalld service on AlmaLinux OS 9 must be active.
Medium Severity
"Firewalld" provides an easy and effective way to block/limit remote access to the system via ports, services, and protocols. Remote access services, such as those providing remote access to network devices and information systems, which lack automated control capabilities, increase risk and make remote user access management difficult at best. Remote access is access to DOD nonpublic information systems by an authorized user (or an information system) communicating through an external, nonorganization-controlled network. Remote access methods include, for example, dial-up, broadband, and wireless. AlmaLinux OS 9 functionality (e.g., SSH) must be capable of taking enforcement action if the audit reveals unauthorized activity. Automated control of remote access sessions allows organizations to ensure ongoing compliance with remote access policies by enforcing connection rules of remote access applications on a variety of information system components (e.g., servers, workstations, notebook computers, smartphones, and tablets). Satisfies: SRG-OS-000480-GPOS-00232, SRG-OS-000096-GPOS-00050, SRG-OS-000297-GPOS-00115
SRG-OS-000480-GPOS-00227
1 Rule
AlmaLinux OS 9 firewall must employ a deny-all, allow-by-exception policy for allowing connections to other systems.
Medium Severity
Failure to restrict network connectivity only to authorized systems permits inbound connections from malicious systems. It also permits outbound connections that may facilitate exfiltration of DOD data. AlmaLinux OS 9 incorporates the "firewalld" daemon, which allows for many different configurations. One of these configurations is zones. Zones can be used to a deny-all, allow-by-exception approach. The default "drop" zone will drop all incoming network packets unless it is explicitly allowed by the configuration file or is related to an outgoing network connection.
SRG-OS-000480-GPOS-00227
1 Rule
AlmaLinux OS 9 must limit the number of bogus Internet Control Message Protocol (ICMP) response errors logs.
Medium Severity
Some routers will send responses to broadcast frames that violate RFC-1122, which fills up a log file system with many useless error messages. An attacker may take advantage of this and attempt to flood the logs with bogus error logs. Ignoring bogus ICMP error responses reduces log size, although some activity would not be logged.
SRG-OS-000480-GPOS-00227
1 Rule
AlmaLinux OS 9 must not respond to Internet Control Message Protocol (ICMP) echoes sent to a broadcast address.
Medium Severity
Responding to broadcast (ICMP) echoes facilitates network mapping and provides a vector for amplification attacks. Ignoring ICMP echo requests (pings) sent to broadcast or multicast addresses makes the system slightly more difficult to enumerate on the network.
SRG-OS-000480-GPOS-00227
1 Rule
AlmaLinux OS 9 must not enable IP packet forwarding unless the system is a router.
Medium Severity
Routing protocol daemons are typically used on routers to exchange network topology information with other routers. If this capability is used when not required, system network information may be unnecessarily transmitted across the network.
SRG-OS-000480-GPOS-00227
1 Rule
AlmaLinux OS 9 must not have unauthorized IP tunnels configured.
Medium Severity
IP tunneling mechanisms can be used to bypass network filtering. If tunneling is required, it must be documented with the information system security officer (ISSO).
SRG-OS-000480-GPOS-00227
1 Rule
AlmaLinux OS 9 must log packets with impossible addresses.
Medium Severity
The presence of "martian" packets (which have impossible addresses) as well as spoofed packets, source-routed packets, and redirects could be a sign of nefarious network activity. Logging these packets enables this activity to be detected.
SRG-OS-000480-GPOS-00227
1 Rule
AlmaLinux OS 9 must be configured to prevent unrestricted mail relaying.
Medium Severity
If unrestricted mail relaying is permitted, unauthorized senders could use this host as a mail relay for the purpose of sending spam or other unauthorized activity.
SRG-OS-000480-GPOS-00227
1 Rule
AlmaLinux OS 9 must have the nss-tools package installed.
Medium Severity
Network Security Services (NSS) is a set of libraries designed to support cross-platform development of security-enabled client and server applications. Install the "nss-tools" package to install command-line tools to manipulate the NSS certificate and key database.
SRG-OS-000480-GPOS-00227
1 Rule
AlmaLinux OS 9 network interfaces must not be in promiscuous mode.
Medium Severity
Network interfaces in promiscuous mode allow for the capture of all network traffic visible to the system. If unauthorized individuals can access these applications, it may allow them to collect information such as logon IDs, passwords, and key exchanges between systems. If the system is being used to perform a network troubleshooting function, the use of these tools must be documented with the information system security officer (ISSO) and restricted to only authorized personnel.
SRG-OS-000480-GPOS-00227
1 Rule
AlmaLinux OS 9 must use reverse path filtering on all IP interfaces.
Medium Severity
Enabling reverse path filtering drops packets with source addresses that should not have been able to be received on the interface on which they were received. It must not be used on systems that are routers for complicated networks, but is helpful for end hosts and routers serving small networks.
SRG-OS-000480-GPOS-00227
1 Rule
AlmaLinux OS 9 must not send Internet Control Message Protocol (ICMP) redirects.
Medium Severity
ICMP redirect messages are used by routers to inform hosts that a more direct route exists for a particular destination. These messages contain information from the system's route table possibly revealing portions of the network topology. The ability to send ICMP redirects is only appropriate for systems acting as routers.
SRG-OS-000480-GPOS-00227
1 Rule
There must be no .shosts files on AlmaLinux OS 9.
Medium Severity
The .shosts files are used to configure host-based authentication for individual users or the system via SSH. Host-based authentication is not sufficient for preventing unauthorized access to the system, as it does not require interactive identification and authentication of a connection request, or for the use of two-factor authentication.
SRG-OS-000480-GPOS-00227
1 Rule
There must be no shosts.equiv files on AlmaLinux OS 9.
Medium Severity
The shosts.equiv files are used to configure host-based authentication for the system via SSH. Host-based authentication is not sufficient for preventing unauthorized access to the system, as it does not require interactive identification and authentication of a connection request, or for the use of two-factor authentication.
SRG-OS-000480-GPOS-00227
1 Rule
AlmaLinux OS 9 must not forward source-routed packets.
Medium Severity
Source-routed packets allow the source of the packet to suggest routers forward the packet along a different path than configured on the router, which can be used to bypass network security measures. This requirement applies only to the forwarding of source-routed traffic, such as when IP forwarding is enabled and the system is functioning as a router. Accepting source-routed packets has few legitimate uses. It must be disabled unless it is absolutely required.
SRG-OS-000480-GPOS-00227
1 Rule
AlmaLinux OS 9 SSH daemon must not allow compression or must only allow compression after successful authentication.
Medium Severity
If compression is allowed in an SSH connection prior to authentication, vulnerabilities in the compression software could result in compromise of the system from an unauthenticated connection, potentially with root privileges.
SRG-OS-000480-GPOS-00227
1 Rule
The AlmaLinux OS 9 SSH server configuration file must be group-owned by root.
Medium Severity
Service configuration files enable or disable features of their respective services, which if configured incorrectly, can lead to insecure and vulnerable configurations. Therefore, service configuration files must be owned by the correct group to prevent unauthorized changes.
SRG-OS-000480-GPOS-00227
1 Rule
The AlmaLinux OS 9 SSH server configuration file must be owned by root.
Medium Severity
Service configuration files enable or disable features of their respective services, which, if configured incorrectly, can lead to insecure and vulnerable configurations. Therefore, service configuration files must be owned by the correct group to prevent unauthorized changes.
SRG-OS-000480-GPOS-00227
1 Rule
AlmaLinux OS 9 SSH server configuration files must have mode 0600 or less permissive.
Medium Severity
Service configuration files enable or disable features of their respective services, which if configured incorrectly, can lead to insecure and vulnerable configurations. Therefore, service configuration files must be owned by the correct group to prevent unauthorized changes.
SRG-OS-000480-GPOS-00227
1 Rule
AlmaLinux OS 9 must not allow a noncertificate trusted host SSH logon to the system.
Medium Severity
SSH trust relationships mean a compromise on one host can allow an attacker to move trivially to other hosts.
SRG-OS-000480-GPOS-00227
1 Rule
AlmaLinux OS 9 SSH private host key files must have mode 0640 or less permissive.
Medium Severity
If an unauthorized user obtains the private SSH host key file, the host could be impersonated.
SRG-OS-000480-GPOS-00227
1 Rule
AlmaLinux OS 9 SSH public host key files must have mode 0644 or less permissive.
Medium Severity
If a public host key file is modified by an unauthorized user, the SSH service may be compromised. Whilst public keys are publicly readable, they should not be writeable by nonowners.
SRG-OS-000480-GPOS-00227
1 Rule
AlmaLinux OS 9 SSH daemon must not allow known hosts authentication.
Medium Severity
Configuring the IgnoreUserKnownHosts setting for the SSH daemon provides additional assurance that remote login via SSH will require a password, even in the event of misconfiguration elsewhere.
SRG-OS-000480-GPOS-00227
1 Rule
AlmaLinux OS 9 SSH daemon must display the date and time of the last successful account logon upon an SSH logon.
Medium Severity
Providing users feedback on when account accesses last occurred facilitates user recognition and reporting of unauthorized account use.
SRG-OS-000480-GPOS-00227
1 Rule
AlmaLinux OS 9 SSH daemon must not allow rhosts authentication.
Medium Severity
SSH trust relationships mean a compromise on one host can allow an attacker to move trivially to other hosts.
SRG-OS-000480-GPOS-00227
1 Rule
AlmaLinux OS 9 SSH daemon must disable remote X connections for interactive users.
Medium Severity
When X11 forwarding is enabled, there may be additional exposure to the server and client displays if the sshd proxy display is configured to listen on the wildcard address. By default, sshd binds the forwarding server to the loopback address and sets the hostname part of the DISPLAY environment variable to localhost. This prevents remote hosts from connecting to the proxy display.
SRG-OS-000480-GPOS-00227
1 Rule
AlmaLinux OS 9 SSH daemon must prevent remote hosts from connecting to the proxy display.
Medium Severity
When X11 forwarding is enabled, there may be additional exposure to the server and client displays if the sshd proxy display is configured to listen on the wildcard address. By default, sshd binds the forwarding server to the loopback address and sets the hostname part of the "DISPLAY" environment variable to localhost. This prevents remote hosts from connecting to the proxy display.
SRG-OS-000480-GPOS-00227
1 Rule
If the Trivial File Transfer Protocol (TFTP) server is required, the TFTP daemon must be configured to operate in secure mode.
Medium Severity
Restricting TFTP to a specific directory prevents remote users from copying, transferring, or overwriting system files. Using the "-s" option causes the TFTP service to only serve files from the given directory.
SRG-OS-000480-GPOS-00227
1 Rule
AlmaLinux OS 9 must enable hardening for the Berkeley Packet Filter (BPF) just-in-time (JIT) compiler.
Medium Severity
When hardened, the extended BPF JIT compiler will randomize any kernel addresses in the BPF programs and maps, and will not expose the JIT addresses in "/proc/kallsyms".
SRG-OS-000480-GPOS-00227
1 Rule
AlmaLinux OS 9 effective dconf policy must match the policy keyfiles.
Medium Severity
Unlike text-based keyfiles, the binary database is impossible to check through most automated and all manual means; therefore, to evaluate dconf configuration, both have to be true at the same time—configuration files have to be compliant, and the database needs to be more recent than those keyfiles, which gives confidence that it reflects them.
SRG-OS-000480-GPOS-00227
1 Rule
AlmaLinux OS 9 must be configured so that all system device files are correctly labeled to prevent unauthorized modification.
Medium Severity
If an unauthorized or modified device is allowed to exist on the system, there is the possibility the system may perform unintended or unauthorized operations.
SRG-OS-000480-GPOS-00227
1 Rule
All AlmaLinux OS 9 local initialization files must have mode 0740 or less permissive.
Medium Severity
Local initialization files are used to configure the user's shell environment upon logon. Malicious modification of these files could compromise accounts upon logon. World-readable "dot files" such as .bash_history or .netrc can reveal plaintext credentials, such files should be further protected (e.g., 0600).
SRG-OS-000480-GPOS-00227
1 Rule
AlmaLinux OS 9 must have the gnutls-utils package installed.
Medium Severity
GnuTLS is a secure communications library implementing the SSL, TLS, and DTLS protocols and technologies around them. It provides a simple C language application programming interface (API) to access the secure communications protocols as well as APIs to parse and write X.509, PKCS #12, OpenPGP, and other required structures. This package contains command line TLS client and server and certificate manipulation tools.
SRG-OS-000480-GPOS-00227
1 Rule
The kdump service on AlmaLinux OS 9 must be disabled.
Medium Severity
Kernel core dumps may contain the full contents of system memory at the time of the crash. Kernel core dumps consume a considerable amount of disk space and may result in denial of service by exhausting the available space on the target file system partition. Unless the system is used for kernel development or testing, there is little need to run the kdump service.
SRG-OS-000480-GPOS-00227
1 Rule
AlmaLinux OS 9 must disable the ability of a user to restart the system from the login screen.
Medium Severity
A user who is at the console can reboot the system at the login screen. If restart or shutdown buttons are pressed at the login screen, this can create the risk of short-term loss of availability of systems due to reboot.
SRG-OS-000480-GPOS-00227
1 Rule
AlmaLinux OS 9 must prevent a user from overriding the disable-restart-buttons setting for the graphical user interface.
Medium Severity
A user who is at the console can reboot the system at the login screen. If restart or shutdown buttons are pressed at the login screen, this can create the risk of short-term loss of availability of systems due to reboot.
SRG-OS-000480-GPOS-00227
1 Rule
AlmaLinux OS 9 must prevent special devices on file systems that are used with removable media.
Medium Severity
The "nodev" mount option causes the system not to interpret character or block special devices. Executing character or blocking special devices from untrusted file systems increases the opportunity for nonprivileged users to attain unauthorized administrative access.
SRG-OS-000480-GPOS-00227
1 Rule
AlmaLinux OS 9 must prevent code from being executed on file systems that are used with removable media.
Medium Severity
The "noexec" mount option causes the system to not execute binary files. This option must be used for mounting any file system not containing approved binary files, as they may be incompatible. Executing files from untrusted file systems increases the opportunity for nonprivileged users to attain unauthorized administrative access.
SRG-OS-000480-GPOS-00227
1 Rule
AlmaLinux OS 9 must prevent files with the setuid and setgid bit set from being executed on file systems that are used with removable media.
Medium Severity
The "nosuid" mount option causes the system to not execute "setuid" and "setgid" files with owner privileges. This option must be used for mounting any file system not containing approved "setuid" and "setguid" files. Executing files from untrusted file systems increases the opportunity for nonprivileged users to attain unauthorized administrative access.
SRG-OS-000480-GPOS-00227
1 Rule
AlmaLinux OS 9 must disable the use of user namespaces.
Medium Severity
User namespaces are used primarily for Linux containers. The value "0" disallows the use of user namespaces.
SRG-OS-000480-GPOS-00227
1 Rule
AlmaLinux OS 9 must prevent special devices on file systems that are imported via Network File System (NFS).
Medium Severity
The "nodev" mount option causes the system to not interpret character or block special devices. Executing character or block special devices from untrusted file systems increases the opportunity for nonprivileged users to attain unauthorized administrative access.
SRG-OS-000480-GPOS-00227
1 Rule
AlmaLinux OS 9 must prevent code execution on file systems that are imported via Network File System (NFS).
Medium Severity
The "noexec" mount option causes the system to not execute binary files. This option must be used for mounting any file system not containing approved binary as they may be incompatible. Executing files from untrusted file systems increases the opportunity for nonprivileged users to attain unauthorized administrative access.
SRG-OS-000480-GPOS-00227
1 Rule
AlmaLinux OS 9 must prevent files with the setuid and setgid bit set from being executed on file systems that are imported via Network File System (NFS).
Medium Severity
The "nosuid" mount option causes the system not to execute "setuid" and "setgid" files with owner privileges. This option must be used for mounting any file system not containing approved "setuid" and "setguid" files. Executing files from untrusted file systems increases the opportunity for nonprivileged users to attain unauthorized administrative access.
SRG-OS-000480-GPOS-00227
1 Rule
AlmaLinux OS 9 must configure a DNS processing mode set be Network Manager.
Medium Severity
To ensure that DNS resolver settings are respected, a DNS mode in Network Manager must be configured.
SRG-OS-000480-GPOS-00227
1 Rule
AlmaLinux OS 9 systems using Domain Name Servers (DNS) resolution must have at least two name servers configured.
Medium Severity
To provide availability for name resolution services, multiple redundant name servers are mandated. A failure in name resolution could lead to the failure of security functions requiring name resolution, which may include time synchronization, centralized authentication, and remote system logging.
SRG-OS-000480-GPOS-00227
1 Rule
AlmaLinux OS 9 must prevent special devices on nonroot local partitions.
Medium Severity
The "nodev" mount option causes the system to not interpret character or block special devices. Executing character or block special devices from untrusted file systems increases the opportunity for nonprivileged users to attain unauthorized administrative access. The only legitimate location for device files is the "/dev" directory located on the root partition, with the exception of chroot jails if implemented.
SRG-OS-000480-GPOS-00227
1 Rule
The root account must be the only account having unrestricted access to an AlmaLinux OS 9 system.
Medium Severity
An account has root authority if it has a user identifier (UID) of "0". Multiple accounts with a UID of "0" afford more opportunity for potential intruders to guess a password for a privileged account. Proper configuration of sudo is recommended to afford multiple system administrators access to root privileges in an accountable manner.
SRG-OS-000480-GPOS-00227
1 Rule
AlmaLinux OS 9 must be configured so that the cryptographic hashes of system files match vendor values.
Medium Severity
The hashes of important files like system executables should match the information given by the RPM database. Executables with erroneous hashes could be a sign of nefarious activity on the system.
SRG-OS-000480-GPOS-00227
1 Rule
AlmaLinux OS 9 must clear the page allocator to prevent use-after-free attacks.
Medium Severity
Poisoning writes an arbitrary value to freed pages, so any modification or reference to that page after being freed or before being initialized will be detected and prevented. This prevents many types of use-after-free vulnerabilities at little performance cost. This also prevents data leaks and detects corrupted memory.
SRG-OS-000480-GPOS-00227
1 Rule
AlmaLinux OS 9 must display the date and time of the last successful account logon upon logon.
Medium Severity
Users need to be aware of activity that occurs regarding their account. Providing users with information regarding the number of unsuccessful attempts that were made to login to their account allows the user to determine if any unauthorized activity has occurred and gives them an opportunity to notify administrators.
SRG-OS-000480-GPOS-00227
1 Rule
AlmaLinux OS 9 security patches and updates must be installed and up to date.
Medium Severity
Installing software updates is a fundamental mitigation against the exploitation of publicly known vulnerabilities. If the most recent security patches and updates are not installed, unauthorized users may take advantage of weaknesses in the unpatched software. The lack of prompt attention to patching could result in a system compromise.
SRG-OS-000480-GPOS-00227
1 Rule
AlmaLinux OS 9 policycoreutils-python-utils package must be installed.
Medium Severity
The policycoreutils-python-utils package is required to operate and manage an SELinux environment and its policies. It provides utilities such as semanage, audit2allow, audit2why, chcat, and sandbox.
SRG-OS-000480-GPOS-00227
1 Rule
AlmaLinux OS 9 must enable the hardware random number generator entropy gatherer service.
Medium Severity
The most important characteristic of a random number generator is its randomness, specifically its ability to deliver random numbers that are impossible to predict. Entropy in computer security is associated with the unpredictability of a source of randomness. The random source with high entropy tends to achieve a uniform distribution of random values. Random number generators are one of the most important building blocks of cryptosystems. The rngd service feeds random data from hardware device to kernel random device. Quality (nonpredictable) random number generation is important for several security functions (i.e., ciphers).
SRG-OS-000480-GPOS-00227
1 Rule
AlmaLinux OS 9 must have the rng-tools package installed.
Medium Severity
"rng-tools" provides hardware random number generator tools, such as those used in the formation of x509/PKI certificates.
SRG-OS-000480-GPOS-00230
1 Rule
The SSH daemon must perform strict mode checking of home directory configuration files.
Medium Severity
If other users have access to modify user-specific SSH configuration files or read keys, they may be able to log into the system as another user.
SRG-OS-000480-GPOS-00227
1 Rule
AlmaLinux OS 9 system accounts must not have an interactive login shell.
Medium Severity
Ensuring shells are not given to system accounts upon login makes it more difficult for attackers to make use of system accounts.
SRG-OS-000480-GPOS-00227
1 Rule
AlmaLinux OS 9 must use a separate file system for /tmp.
Medium Severity
The "/tmp" partition is used as temporary storage by many programs. Placing "/tmp" in its own partition enables the setting of more restrictive mount options, which can help protect programs that use it.
SRG-OS-000480-GPOS-00227
1 Rule
Local AlmaLinux OS 9 initialization files must not execute world-writable programs.
Medium Severity
If user start-up files execute world-writable programs, especially in unprotected directories, they could be maliciously modified to destroy user files or otherwise compromise the system at the user level. If the system is compromised at the user level, it is easier to elevate privileges to eventually compromise the system at the root and network level.
SRG-OS-000480-GPOS-00227
1 Rule
AlmaLinux OS 9 must use a separate file system for /var/log.
Medium Severity
Placing "/var/log" in its own partition enables better separation between log files and other files in "/var/".
SRG-OS-000480-GPOS-00227
1 Rule
AlmaLinux OS 9 must use a separate file system for /var.
Medium Severity
Ensuring that "/var" is mounted on its own partition enables the setting of more restrictive mount options. This helps protect system services such as daemons or other programs which use it. It is not uncommon for the "/var" directory to contain world-writable directories installed by other software packages.
SRG-OS-000480-GPOS-00227
1 Rule
AlmaLinux OS 9 must use a separate file system for /var/tmp.
Medium Severity
The "/var/tmp" partition is used as temporary storage by many programs. Placing "/var/tmp" in its own partition enables the setting of more restrictive mount options, which can help protect programs that use it.
SRG-OS-000480-GPOS-00227
1 Rule
AlmaLinux OS 9 must disable virtual system calls.
Medium Severity
System calls are special routines in the Linux kernel, which userspace applications ask to do privileged tasks. Invoking a system call is an expensive operation because the processor must interrupt the currently executing task and switch context to kernel mode, and then switch back to userspace after the system call completes. Virtual system calls map a page into userspace that contains some variables and the implementation of some system calls. This allows the system calls to be executed in userspace to alleviate the context switching expense. Virtual system calls provide an opportunity of attack for a user who has control of the return instruction pointer. Disabling virtual system calls help to prevent return oriented programming (ROP) attacks via buffer overflows and overruns.
SRG-OS-000480-GPOS-00227
1 Rule
AlmaLinux OS 9 must use cron logging.
Medium Severity
Cron logging can be used to trace the successful or unsuccessful execution of cron jobs. It can also be used to spot intrusions into the use of the cron facility by unauthorized and malicious users.
SRG-OS-000480-GPOS-00227
1 Rule
AlmaLinux OS 9 must be configured so that the rsyslog daemon does not accept log messages from other servers unless the server is being used for log aggregation.
Medium Severity
Unintentionally running a rsyslog server accepting remote messages puts the system at increased risk. Malicious rsyslog messages sent to the server could exploit vulnerabilities in the server software itself, could introduce misleading information into the system's logs, or could fill the system's storage leading to a denial of service. If the system is intended to be a log aggregation server, its use must be documented with the information system security officer (ISSO).
SRG-OS-000480-GPOS-00230
1 Rule
AlmaLinux OS 9 must prevent files with the setuid and setgid bit set from being executed on file systems that contain user home directories.
Medium Severity
The "nosuid" mount option causes the system to not execute "setuid" and "setgid" files with owner privileges. This option must be used for mounting any file system not containing approved "setuid" and "setguid" files. Executing files from untrusted file systems increases the opportunity for nonprivileged users to attain unauthorized administrative access. Satisfies: SRG-OS-000480-GPOS-00230, SRG-OS-000368-GPOS-00154
SRG-OS-000368-GPOS-00154
1 Rule
AlmaLinux OS 9 must prevent device files from being interpreted on file systems that contain user home directories.
Medium Severity
The "nodev" mount option causes the system to not interpret character or block special devices. Executing character or block special devices from untrusted file systems increases the opportunity for nonprivileged users to attain unauthorized administrative access. The only legitimate location for device files is the "/dev" directory located on the root partition, with the exception of chroot jails if implemented.
SRG-OS-000368-GPOS-00154
1 Rule
AlmaLinux OS 9 must prevent files with the setuid and setgid bit set from being executed on the /boot/efi directory.
Medium Severity
The "nosuid" mount option causes the system not to execute "setuid" and "setgid" files with owner privileges. This option must be used for mounting any file system not containing approved "setuid" and "setguid" files. Executing files from untrusted file systems increases the opportunity for nonprivileged users to attain unauthorized administrative access.
SRG-OS-000368-GPOS-00154
1 Rule
AlmaLinux OS 9 must mount /boot with the nodev option.
Medium Severity
The only legitimate location for device files is the "/dev" directory located on the root partition. The only exception to this is chroot jails.
SRG-OS-000368-GPOS-00154
1 Rule
AlmaLinux OS 9 must prevent files with the setuid and setgid bit set from being executed on the /boot directory.
Medium Severity
The "nosuid" mount option causes the system not to execute "setuid" and "setgid" files with owner privileges. This option must be used for mounting any file system not containing approved "setuid" and "setguid" files. Executing files from untrusted file systems increases the opportunity for nonprivileged users to attain unauthorized administrative access.
SRG-OS-000368-GPOS-00154
1 Rule
AlmaLinux OS 9 must mount /dev/shm with the nodev option.
Medium Severity
The "nodev" mount option causes the system to not interpret character or block special devices. Executing character or block special devices from untrusted file systems increases the opportunity for nonprivileged users to attain unauthorized administrative access. The only legitimate location for device files is the "/dev" directory located on the root partition, with the exception of chroot jails if implemented.
SRG-OS-000368-GPOS-00154
1 Rule
AlmaLinux OS 9 must mount /dev/shm with the noexec option.
Medium Severity
The "noexec" mount option causes the system to not execute binary files. This option must be used for mounting any file system not containing approved binary files, as they may be incompatible. Executing files from untrusted file systems increases the opportunity for nonprivileged users to attain unauthorized administrative access.
SRG-OS-000368-GPOS-00154
1 Rule
AlmaLinux OS 9 must mount /dev/shm with the nosuid option.
Medium Severity
The "nosuid" mount option causes the system to not execute "setuid" and "setgid" files with owner privileges. This option must be used for mounting any file system not containing approved "setuid" and "setguid" files. Executing files from untrusted file systems increases the opportunity for nonprivileged users to attain unauthorized administrative access.
SRG-OS-000368-GPOS-00154
1 Rule
AlmaLinux OS 9 must mount /tmp with the nodev option.
Medium Severity
The "nodev" mount option causes the system to not interpret character or block special devices. Executing character or block special devices from untrusted file systems increases the opportunity for nonprivileged users to attain unauthorized administrative access. The only legitimate location for device files is the "/dev" directory located on the root partition, with the exception of chroot jails if implemented.
SRG-OS-000368-GPOS-00154
1 Rule
AlmaLinux OS 9 must mount /tmp with the noexec option.
Medium Severity
The "noexec" mount option causes the system to not execute binary files. This option must be used for mounting any file system not containing approved binary files, as they may be incompatible. Executing files from untrusted file systems increases the opportunity for nonprivileged users to attain unauthorized administrative access.
SRG-OS-000368-GPOS-00154
1 Rule
AlmaLinux OS 9 must mount /tmp with the nosuid option.
Medium Severity
The "nosuid" mount option causes the system to not execute "setuid" and "setgid" files with owner privileges. This option must be used for mounting any file system not containing approved "setuid" and "setguid" files. Executing files from untrusted file systems increases the opportunity for nonprivileged users to attain unauthorized administrative access.
SRG-OS-000368-GPOS-00154
1 Rule
AlmaLinux OS 9 must mount /var/log/audit with the nodev option.
Medium Severity
The "nodev" mount option causes the system to not interpret character or block special devices. Executing character or block special devices from untrusted file systems increases the opportunity for nonprivileged users to attain unauthorized administrative access. The only legitimate location for device files is the "/dev" directory located on the root partition, with the exception of chroot jails if implemented.
SRG-OS-000368-GPOS-00154
1 Rule
AlmaLinux OS 9 must mount /var/log/audit with the noexec option.
Medium Severity
The "noexec" mount option causes the system to not execute binary files. This option must be used for mounting any file system not containing approved binary files, as they may be incompatible. Executing files from untrusted file systems increases the opportunity for nonprivileged users to attain unauthorized administrative access.
SRG-OS-000368-GPOS-00154
1 Rule
AlmaLinux OS 9 must mount /var/log/audit with the nosuid option.
Medium Severity
The "nosuid" mount option causes the system to not execute "setuid" and "setgid" files with owner privileges. This option must be used for mounting any file system not containing approved "setuid" and "setguid" files. Executing files from untrusted file systems increases the opportunity for nonprivileged users to attain unauthorized administrative access.
SRG-OS-000368-GPOS-00154
1 Rule
AlmaLinux OS 9 must mount /var/log with the nodev option.
Medium Severity
The "nodev" mount option causes the system to not interpret character or block special devices. Executing character or block special devices from untrusted file systems increases the opportunity for nonprivileged users to attain unauthorized administrative access. The only legitimate location for device files is the "/dev" directory located on the root partition, with the exception of chroot jails if implemented.
SRG-OS-000368-GPOS-00154
1 Rule
AlmaLinux OS 9 must mount /var/log with the noexec option.
Medium Severity
The "noexec" mount option causes the system to not execute binary files. This option must be used for mounting any file system not containing approved binary files, as they may be incompatible. Executing files from untrusted file systems increases the opportunity for nonprivileged users to attain unauthorized administrative access.
SRG-OS-000368-GPOS-00154
1 Rule
AlmaLinux OS 9 must mount /var/log with the nosuid option.
Medium Severity
The "nosuid" mount option causes the system to not execute "setuid" and "setgid" files with owner privileges. This option must be used for mounting any file system not containing approved "setuid" and "setguid" files. Executing files from untrusted file systems increases the opportunity for nonprivileged users to attain unauthorized administrative access.
SRG-OS-000368-GPOS-00154
1 Rule
AlmaLinux OS 9 must mount /var with the nodev option.
Medium Severity
The "nodev" mount option causes the system to not interpret character or block special devices. Executing character or block special devices from untrusted file systems increases the opportunity for nonprivileged users to attain unauthorized administrative access. The only legitimate location for device files is the "/dev" directory located on the root partition, with the exception of chroot jails if implemented.
SRG-OS-000368-GPOS-00154
1 Rule
AlmaLinux OS 9 must mount /var/tmp with the nodev option.
Medium Severity
The "nodev" mount option causes the system to not interpret character or block special devices. Executing character or block special devices from untrusted file systems increases the opportunity for nonprivileged users to attain unauthorized administrative access. The only legitimate location for device files is the "/dev" directory located on the root partition, with the exception of chroot jails if implemented.
SRG-OS-000368-GPOS-00154
1 Rule
AlmaLinux OS 9 must mount /var/tmp with the noexec option.
Medium Severity
The "noexec" mount option causes the system to not execute binary files. This option must be used for mounting any file system not containing approved binary files, as they may be incompatible. Executing files from untrusted file systems increases the opportunity for nonprivileged users to attain unauthorized administrative access.
SRG-OS-000368-GPOS-00154
1 Rule
AlmaLinux OS 9 must mount /var/tmp with the nosuid option.
Medium Severity
The "nosuid" mount option causes the system to not execute "setuid" and "setgid" files with owner privileges. This option must be used for mounting any file system not containing approved "setuid" and "setguid" files. Executing files from untrusted file systems increases the opportunity for nonprivileged users to attain unauthorized administrative access.
SRG-OS-000370-GPOS-00155
1 Rule
AlmaLinux OS 9 fapolicy module must be enabled.
Medium Severity
The organization must identify authorized software programs and permit execution of authorized software. The process used to identify software programs that are authorized to execute on organizational information systems is commonly referred to as allowlisting. Utilizing an allowlist provides a configuration management method for allowing the execution of only authorized software. Using only authorized software decreases risk by limiting the number of potential vulnerabilities. Verification of allowlisted software occurs prior to execution or at system startup. User home directories/folders may contain information of a sensitive nature. Nonprivileged users should coordinate any sharing of information with a system administrator (SA) through shared resources. AlmaLinux OS 9 ships with many optional packages. One such package is a file access policy daemon called "fapolicyd". "fapolicyd" is a userspace daemon that determines access rights to files based on attributes of the process and file. It can be used to either blocklist or allowlist processes or file access. Proceed with caution with enforcing the use of this daemon. Improper configuration may render the system nonfunctional. The "fapolicyd" API is not namespace aware and can cause issues when launching or running containers.
SRG-OS-000370-GPOS-00155
1 Rule
AlmaLinux OS 9 fapolicy module must be installed.
Medium Severity
The organization must identify authorized software programs and permit execution of authorized software. The process used to identify software programs that are authorized to execute on organizational information systems is commonly referred to as allowlisting. Utilizing an allowlist provides a configuration management method for allowing the execution of only authorized software. Using only authorized software decreases risk by limiting the number of potential vulnerabilities. Verification of allowlisted software occurs prior to execution or at system startup. User home directories/folders may contain information of a sensitive nature. Nonprivileged users should coordinate any sharing of information with a system administrator (SA) through shared resources. AlmaLinux OS 9 ships with many optional packages. One such package is a file access policy daemon called "fapolicyd". "fapolicyd" is a userspace daemon that determines access rights to files based on attributes of the process and file. It can be used to either blocklist or allowlist processes or file access. Proceed with caution with enforcing the use of this daemon. Improper configuration may render the system nonfunctional. The "fapolicyd" API is not namespace aware and can cause issues when launching or running containers.
SRG-OS-000095-GPOS-00049
1 Rule
AlmaLinux OS 9 must disable remote management of the chrony daemon.
Medium Severity
Not exposing the management interface of the chrony daemon on the network reduces the attack surface.
SRG-OS-000095-GPOS-00049
1 Rule
AlmaLinux OS 9 must prevent the chrony daemon from acting as a server.
Medium Severity
Being able to determine the system time of a server can be useful information for various attacks from timebomb attacks to location discovery based on time zone. Minimizing the exposure of the server functionality of the chrony daemon reduces the attack surface.
SRG-OS-000095-GPOS-00049
1 Rule
AlmaLinux OS 9 must not have the iprutils package installed.
Medium Severity
The iprutils package provides a suite of utilities to manage and configure SCSI devices supported by the ipr SCSI storage device driver.
SRG-OS-000095-GPOS-00049
1 Rule
AlmaLinux OS 9 must not have the quagga package installed.
Medium Severity
Quagga is a network routing software suite providing implementations of Open Shortest Path First (OSPF), Routing Information Protocol (RIP), Border Gateway Protocol (BGP) for Unix and Linux platforms. If there is no need to make the router software available, removing it provides a safeguard against its activation.
SRG-OS-000095-GPOS-00049
1 Rule
AlmaLinux OS 9 must not have the sendmail package installed.
Medium Severity
The sendmail software was not developed with security in mind, and its design prevents it from being effectively contained by SELinux. Postfix must be used instead.
SRG-OS-000095-GPOS-00049
1 Rule
AlmaLinux OS 9 must not have the telnet-server package installed.
Medium Severity
It is detrimental for operating systems to provide, or install by default, functionality exceeding requirements or mission objectives. These unnecessary capabilities are often overlooked and therefore, may remain unsecure. They increase the risk to the platform by providing additional attack vectors. The telnet service provides an unencrypted remote access service, which does not provide for the confidentiality and integrity of user passwords or the remote session. If a privileged user were to login using this service, the privileged user password could be compromised. Removing the "telnet-server" package decreases the risk of accidental (or intentional) activation of the telnet service.
SRG-OS-000095-GPOS-00049
1 Rule
AlmaLinux OS 9 must not have a Trivial File Transfer Protocol (TFTP) client package installed.
Medium Severity
If TFTP is required for operational support (such as transmission of router configurations), its use must be documented with the information systems security manager (ISSM), restricted to only authorized personnel, and have access control rules established.
SRG-OS-000095-GPOS-00049
1 Rule
AlmaLinux OS 9 must not have the cups package installed.
Medium Severity
The cups package provides printer drivers as well as a print server, webserver, and discovery mechanisms. Removing the package reduces the potential attack surface.
SRG-OS-000095-GPOS-00049
1 Rule
AlmaLinux OS 9 must not have the gssproxy package installed.
Medium Severity
The gssproxy package is a proxy for GSS API credential handling and could expose secrets on some networks. It is not needed for normal function of the OS.
SRG-OS-000095-GPOS-00049
1 Rule
AlmaLinux OS 9 must disable the Asynchronous Transfer Mode (ATM) kernel module.
Medium Severity
The ATM is a transport layer protocol designed for digital transmission of multiple types of traffic, including telephony (voice), data, and video signals, in one network without the use of separate overlay networks. Disabling ATM protects the system against exploitation of any flaws in its implementation.
SRG-OS-000095-GPOS-00049
1 Rule
AlmaLinux OS 9 must be configured to disable Bluetooth.
Medium Severity
This requirement applies to wireless peripheral technologies (e.g., wireless mice, keyboards, displays, etc.) used with AlmaLinux OS 9 systems. Wireless peripherals (e.g., Wi-Fi/Bluetooth/IR keyboards, mice and pointing devices, and near field communications [NFC]) present a unique challenge by creating an open, unsecured port on a computer. Wireless peripherals must meet DOD requirements for wireless data transmission and be approved for use by the authorizing official (AO). Even though some wireless peripherals, such as mice and pointing devices, do not ordinarily carry information that need to be protected, modification of communications with these wireless peripherals may be used to compromise the AlmaLinux OS 9 operating system.
SRG-OS-000095-GPOS-00049
1 Rule
AlmaLinux OS 9 must disable the Controller Area Network (CAN) kernel module.
Medium Severity
The CAN protocol is a robust vehicle bus standard designed to allow microcontrollers and devices to communicate with each other's applications without a host computer. Disabling CAN protects the system against exploitation of any flaws in its implementation.
SRG-OS-000095-GPOS-00049
1 Rule
AlmaLinux OS 9 must disable mounting of cramfs.
Medium Severity
Removing support for unneeded filesystem types reduces the local attack surface of the server. Compressed ROM/RAM file system (or cramfs) is a read-only file system designed for simplicity and space-efficiency. It is mainly used in embedded and small-footprint systems.
SRG-OS-000095-GPOS-00049
1 Rule
AlmaLinux OS 9 must disable the Stream Control Transmission Protocol (SCTP) kernel module.
Medium Severity
The SCTP is a transport layer protocol, designed to support the idea of message-oriented communication, with several streams of messages within one connection. Disabling SCTP protects the system against exploitation of any flaws in its implementation.
SRG-OS-000095-GPOS-00049
1 Rule
AlmaLinux OS 9 must disable mounting of squashfs.
Medium Severity
Removing support for unneeded filesystem types reduces the local attack surface of the server. A squashfs compressed filesystem image can be mounted without first decompressing the image. Note that Snap packages use squashfs.
SRG-OS-000095-GPOS-00049
1 Rule
AlmaLinux OS 9 must disable the Transparent Inter Process Communication (TIPC) kernel module.
Medium Severity
It is detrimental for operating systems to provide, or install by default, functionality exceeding requirements or mission objectives. These unnecessary capabilities or services are often overlooked and therefore may remain unsecured. They increase the risk to the platform by providing additional attack vectors. Failing to disconnect unused protocols can result in a system compromise. The TIPC is a protocol that is specially designed for intra-cluster communication. It can be configured to transmit messages either on UDP or directly across Ethernet. Message delivery is sequence guaranteed, loss free and flow controlled. Disabling TIPC protects the system against exploitation of any flaws in its implementation.
SRG-OS-000095-GPOS-00049
1 Rule
AlmaLinux OS 9 must disable mounting of udf.
Medium Severity
Removing support for unneeded filesystem types reduces the local attack surface of the server. The UDF filesystem is used to write DVDs and so could assist in data exfiltration, the so-called "sneakernet". Note that Microsoft Azure uses UDF.
SRG-OS-000095-GPOS-00049
1 Rule
Cameras must be disabled or covered when not in use.
Medium Severity
It is detrimental for operating systems to provide, or install by default, functionality exceeding requirements or mission objectives. These unnecessary capabilities or services are often overlooked and therefore may remain unsecured. They increase the risk to the platform by providing additional attack vectors. Failing to disconnect from collaborative computing devices (i.e., cameras) can result in subsequent compromises of organizational information. Providing easy methods to physically disconnect from such devices after a collaborative computing session helps to ensure participants actually carry out the disconnect activity without having to go through complex and tedious procedures; it also ensures that microphones built into the cameras are also disabled.
SRG-OS-000095-GPOS-00049
1 Rule
AlmaLinux OS 9 must not have the nfs-utils package installed.
Medium Severity
"nfs-utils" provides a daemon for the kernel Network File System (NFS) server and related tools. This package also contains the "showmount" program. "showmount" queries the mount daemon on a remote host for information about the NFS server on the remote host. For example, "showmount" can display the clients that are mounted on that host.
SRG-OS-000095-GPOS-00049
1 Rule
AlmaLinux OS 9 must not have the rsh package installed.
Medium Severity
The "rsh" package provides a client for several obsolete and insecure network services. Removing it decreases the risk of accidental (or intentional) use of those services.
SRG-OS-000095-GPOS-00049
1 Rule
AlmaLinux OS 9 must not have the rsh-server package installed.
Medium Severity
The "rsh-server" service provides unencrypted remote access service, which does not provide for the confidentiality and integrity of user passwords or the remote session and has very weak authentication. If a privileged user were to login using this service, the privileged user password could be compromised. The "rsh-server" package provides several obsolete and insecure network services. Removing it decreases the risk of accidental (or intentional) activation of those services.
SRG-OS-000095-GPOS-00049
1 Rule
AlmaLinux OS 9 must not have the tuned package installed.
Medium Severity
The tuned package contains a daemon that tunes the system settings dynamically. It does so by monitoring the usage of several system components periodically. Based on that information, components will then be put into lower or higher power savings modes to adapt to the current usage. The tuned package is not needed for normal OS operations.
SRG-OS-000095-GPOS-00049
1 Rule
A graphical display manager must not be installed on AlmaLinux OS 9 unless approved.
Medium Severity
Unnecessary service packages must not be installed to decrease the attack surface of the system. Graphical display managers have a long history of security vulnerabilities and must not be used, unless approved and documented.
SRG-OS-000095-GPOS-00049
1 Rule
AlmaLinux OS 9 must not have the ypserv package installed.
Medium Severity
The NIS service provides an unencrypted authentication service, which does not provide for the confidentiality and integrity of user passwords or the remote session. Removing the "ypserv" package decreases the risk of the accidental (or intentional) activation of NIS or NIS+ services.
SRG-OS-000095-GPOS-00049
1 Rule
AlmaLinux OS 9 must not have the avahi package installed.
Medium Severity
The avahi package provides the zeroconf capability to discover remote services such as printers and announce itself as a service for sharing files and devices.
SRG-OS-000095-GPOS-00049
1 Rule
AlmaLinux OS 9 must be configured to disable USB mass storage.
Medium Severity
USB mass storage permits easy introduction of unknown devices, thereby facilitating malicious activity. Satisfies: SRG-OS-000095-GPOS-00049, SRG-OS-000378-GPOS-00163, SRG-OS-000114-GPOS-00059, SRG-OS-000690-GPOS-00140
SRG-OS-000096-GPOS-00050
1 Rule
AlmaLinux OS 9 must have the firewalld package installed.
Medium Severity
"Firewalld" provides an easy and effective way to block/limit remote access to the system via ports, services, and protocols. Remote access services, such as those providing remote access to network devices and information systems, which lack automated control capabilities, increase risk and make remote user access management difficult at best. Remote access is access to DOD nonpublic information systems by an authorized user (or an information system) communicating through an external, nonorganization-controlled network. Remote access methods include, for example, dial-up, broadband, and wireless. AlmaLinux OS 9 functionality (e.g., SSH) must be capable of taking enforcement action if the audit reveals unauthorized activity. Automated control of remote access sessions allows organizations to ensure ongoing compliance with remote access policies by enforcing connection rules of remote access applications on a variety of information system components (e.g., servers, workstations, notebook computers, smartphones, and tablets). Satisfies: SRG-OS-000096-GPOS-00050, SRG-OS-000298-GPOS-00116, SRG-OS-000297-GPOS-00115
SRG-OS-000327-GPOS-00127
1 Rule
AlmaLinux OS 9 must require users to provide authentication for privilege escalation.
Medium Severity
Without re-authentication, users may access resources or perform tasks for which they do not have authorization. When operating systems provide the capability to escalate a functional capability, it is critical the user re-authenticate.
SRG-OS-000327-GPOS-00127
1 Rule
AlmaLinux OS 9 must require users to provide a password for privilege escalation.
Medium Severity
Without re-authentication, users may access resources or perform tasks for which they do not have authorization. When operating systems provide the capability to escalate a functional capability, it is critical the user re-authenticate.
SRG-OS-000327-GPOS-00127
1 Rule
AlmaLinux OS 9 must not be configured to bypass password requirements for privilege escalation.
Medium Severity
Without re-authentication, users may access resources or perform tasks for which they do not have authorization. When operating systems provide the capability to escalate a functional capability, it is critical the user re-authenticate.
SRG-OS-000327-GPOS-00127
1 Rule
AlmaLinux OS 9 must require reauthentication when using the "sudo" command.
Medium Severity
Without re-authentication, users may access resources or perform tasks for which they do not have authorization. When operating systems provide the capability to escalate a functional capability, it is critical the user re-authenticate.
SRG-OS-000109-GPOS-00056
1 Rule
AlmaLinux OS 9 must restrict the use of the "su" command.
Medium Severity
The "su" program provides a "switch user" capability. It is commonly used to become root but can be used to switch to any user. Limiting access to such commands is considered a good security practice. Satisfies: SRG-OS-000109-GPOS-00056, SRG-OS-000312-GPOS-00124, SRG-OS-000312-GPOS-00122, SRG-OS-000312-GPOS-00123
SRG-OS-000104-GPOS-00051
1 Rule
Groups must have unique Group IDs (GIDs).
Medium Severity
To ensure accountability and prevent unauthenticated access, organizational users must be identified and authenticated to prevent potential misuse and compromise of the system. Organizational users include organizational employees or individuals the organization deems to have equivalent status of employees (e.g., contractors). Organizational users (and processes acting on behalf of users) must be uniquely identified and authenticated to all accesses, except for the following: 1) Accesses explicitly identified and documented by the organization. Organizations document specific user actions that can be performed on the information system without identification or authentication; and 2) Accesses that occur through authorized use of group authenticators without individual authentication. Organizations may require unique identification of individuals in group accounts (e.g., shared privilege accounts) or for detailed accountability of individual activity.
SRG-OS-000104-GPOS-00051
1 Rule
Duplicate User IDs (UIDs) must not exist for interactive users.
Medium Severity
To ensure accountability and prevent unauthenticated access, organizational users must be identified and authenticated to prevent potential misuse and compromise of the system. Organizational users include organizational employees or individuals the organization deems to have equivalent status of employees (e.g., contractors). Organizational users (and processes acting on behalf of users) must be uniquely identified and authenticated to all accesses, except for the following: 1) Accesses explicitly identified and documented by the organization. Organizations document specific user actions that can be performed on the information system without identification or authentication; and 2) Accesses that occur through authorized use of group authenticators without individual authentication. Organizations may require unique identification of individuals in group accounts (e.g., shared privilege accounts) or for detailed accountability of individual activity. Satisfies: SRG-OS-000104-GPOS-00051, SRG-OS-000121-GPOS-00062
SRG-OS-000104-GPOS-00051
1 Rule
All AlmaLinux OS 9 interactive users must have a primary group that exists.
Medium Severity
If a user is assigned the Group Identifier (GID) of a group that does not exist on the system, and a group with the GID is subsequently created, the user may have unintended rights to any files associated with the group.
SRG-OS-000105-GPOS-00052
1 Rule
AlmaLinux OS 9 SSHD must accept public key authentication.
Medium Severity
Without the use of multifactor authentication, the ease of access to privileged functions is greatly increased. Multifactor authentication requires using two or more factors to achieve authentication. Factors include: 1) something a user knows (e.g., password/PIN); 2) something a user has (e.g., cryptographic identification device, token); and 3) something a user is (e.g., biometric). A privileged account is defined as an information system account with authorizations of a privileged user. Network access is defined as access to an information system by a user (or a process acting on behalf of a user) communicating through a network (e.g., local area network, wide area network, or the internet). The DOD CAC with DOD-approved PKI is an example of multifactor authentication.
SRG-OS-000375-GPOS-00160
1 Rule
AlmaLinux OS 9 must have the opensc package installed.
Medium Severity
Using an authentication device, such as a CAC or token that is separate from the information system, ensures that even if the information system is compromised, that compromise will not affect credentials stored on the authentication device. Multifactor solutions that require devices separate from information systems gaining access include, for example, hardware tokens providing time-based or challenge-response authenticators and smart cards such as the U.S. Government Personal Identity Verification card and the DOD Common Access Card. A privileged account is defined as an information system account with authorizations of a privileged user. Remote access is access to DOD nonpublic information systems by an authorized user (or an information system) communicating through an external, nonorganization-controlled network. Remote access methods include, for example, dial-up, broadband, and wireless. This requirement only applies to components where this is specific to the function of the device or has the concept of an organizational user (e.g., VPN, proxy capability). This does not apply to authentication for the purpose of configuring the device itself (management). This requires further clarification from NIST.
SRG-OS-000375-GPOS-00160
1 Rule
The pcscd socket on AlmaLinux OS 9 must be active.
Medium Severity
Using an authentication device, such as a CAC or token that is separate from the information system, ensures that even if the information system is compromised, that compromise will not affect credentials stored on the authentication device. Multifactor solutions that require devices separate from information systems gaining access include, for example, hardware tokens providing time-based or challenge-response authenticators and smart cards such as the U.S. Government Personal Identity Verification card and the DOD Common Access Card. A privileged account is defined as an information system account with authorizations of a privileged user. Remote access is access to DOD nonpublic information systems by an authorized user (or an information system) communicating through an external, nonorganization-controlled network. Remote access methods include, for example, dial-up, broadband, and wireless. This requirement only applies to components where this is specific to the function of the device or has the concept of an organizational user (e.g., VPN, proxy capability). This does not apply to authentication for the purpose of configuring the device itself (management). This requires further clarification from NIST.
SRG-OS-000375-GPOS-00160
1 Rule
AlmaLinux OS 9 must have the pcsc-lite package installed.
Medium Severity
Using an authentication device, such as a CAC or token that is separate from the information system, ensures that even if the information system is compromised, that compromise will not affect credentials stored on the authentication device. Multifactor solutions that require devices separate from information systems gaining access include, for example, hardware tokens providing time-based or challenge-response authenticators and smart cards such as the U.S. Government Personal Identity Verification card and the DOD Common Access Card. A privileged account is defined as an information system account with authorizations of a privileged user. Remote access is access to DOD nonpublic information systems by an authorized user (or an information system) communicating through an external, nonorganization-controlled network. Remote access methods include, for example, dial-up, broadband, and wireless. This requirement only applies to components where this is specific to the function of the device or has the concept of an organizational user (e.g., VPN, proxy capability). This does not apply to authentication for the purpose of configuring the device itself (management). This requires further clarification from NIST.
SRG-OS-000375-GPOS-00160
1 Rule
AlmaLinux OS 9 must implement certificate status checking for multifactor authentication.
Medium Severity
Using an authentication device, such as a DOD Common Access Card (CAC) or token that is separate from the information system, ensures that even if the information system is compromised, credentials stored on the authentication device will not be affected. Multifactor solutions that require devices separate from information systems gaining access include, for example, hardware tokens providing time-based or challenge-response authenticators and smart cards such as the U.S. Government Personal Identity Verification (PIV) card and the DOD CAC. AlmaLinux OS 9 includes multiple options for configuring certificate status checking, but for this requirement focuses on the System Security Services Daemon (SSSD). By default, SSSD performs Online Certificate Status Protocol (OCSP) checking and certificate verification using a sha256 digest function.
SRG-OS-000375-GPOS-00160
1 Rule
AlmaLinux OS 9 must enable certificate based smart card authentication.
Medium Severity
Using an authentication device, such as a CAC or token that is separate from the information system, ensures that even if the information system is compromised, that compromise will not affect credentials stored on the authentication device. Multifactor solutions that require devices separate from information systems gaining access include, for example, hardware tokens providing time-based or challenge-response authenticators and smart cards such as the U.S. Government Personal Identity Verification card and the DOD Common Access Card. A privileged account is defined as an information system account with authorizations of a privileged user. Remote access is access to DOD nonpublic information systems by an authorized user (or an information system) communicating through an external, nonorganization-controlled network. Remote access methods include, for example, dial-up, broadband, and wireless. This requirement only applies to components where this is specific to the function of the device or has the concept of an organizational user (e.g., VPN, proxy capability). This does not apply to authentication for the purpose of configuring the device itself (management). This requires further clarification from NIST. Satisfies: SRG-OS-000375-GPOS-00160, SRG-OS-000105-GPOS-00052, SRG-OS-000705-GPOS-00150
SRG-OS-000377-GPOS-00162
1 Rule
AlmaLinux OS 9 must have the openssl-pkcs11 package installed.
Medium Severity
The use of PIV credentials facilitates standardization and reduces the risk of unauthorized access. DOD has mandated the use of the CAC to support identity management and personal authentication for systems covered under Homeland Security Presidential Directive (HSPD) 12, as well as making the CAC a primary component of layered protection for national security systems. Satisfies: SRG-OS-000377-GPOS-00162, SRG-OS-000376-GPOS-00161, SRG-OS-000375-GPOS-00160, SRG-OS-000105-GPOS-00052
SRG-OS-000106-GPOS-00053
1 Rule
AlmaLinux OS 9 SSHD must not allow blank passwords.
Medium Severity
If an account has an empty password, anyone could log on and run commands with the privileges of that account. Accounts with empty passwords should never be used in operational environments. Satisfies: SRG-OS-000106-GPOS-00053, SRG-OS-000108-GPOS-00055
SRG-OS-000107-GPOS-00054
1 Rule
AlmaLinux OS 9 must use the CAC smart card driver.
Medium Severity
Smart card login provides two-factor authentication stronger than that provided by a username and password combination. Smart cards leverage public key infrastructure to provide and verify credentials. Configuring the smart card driver in use by the organization helps to prevent users from using unauthorized smart cards. Satisfies: SRG-OS-000107-GPOS-00054, SRG-OS-000108-GPOS-00055, SRG-OS-000112-GPOS-00057, SRG-OS-000113-GPOS-00058
SRG-OS-000109-GPOS-00056
1 Rule
AlmaLinux OS 9 must not permit direct logons to the root account using remote access via SSH.
Medium Severity
Even though the communications channel may be encrypted, an additional layer of security is gained by extending the policy of not logging directly on as root. In addition, logging in with a user-specific account provides individual accountability of actions performed on the system. The root account is a known default username, so should not allow direct login as half of the username/password combination is known, making it vulnerable to brute-force password guessing attacks.
SRG-OS-000378-GPOS-00163
1 Rule
AlmaLinux OS 9 must disable the graphical user interface automount function unless required.
Medium Severity
Automatically mounting file systems permits easy introduction of unknown devices, thereby facilitating malicious activity. Satisfies: SRG-OS-000378-GPOS-00163, SRG-OS-000114-GPOS-00059
SRG-OS-000378-GPOS-00163
1 Rule
AlmaLinux OS 9 must prevent a user from overriding the disabling of the graphical user interface automount function.
Medium Severity
Automatically mounting file systems permits easy introduction of unknown devices, thereby facilitating malicious activity. Satisfies: SRG-OS-000378-GPOS-00163, SRG-OS-000114-GPOS-00059
SRG-OS-000378-GPOS-00163
1 Rule
AlmaLinux OS 9 must prevent a user from overriding the disabling of the graphical user interface autorun function.
Medium Severity
Automatically mounting filesystems and running applications upon insertion of a device facilitates malicious activity. Satisfies: SRG-OS-000378-GPOS-00163, SRG-OS-000114-GPOS-00059
SRG-OS-000378-GPOS-00163
1 Rule
AlmaLinux OS 9 must have the USBGuard package installed.
Medium Severity
The USBGuard-daemon is the main component of the USBGuard software framework. It runs as a service in the background and enforces the USB device authorization policy for all USB devices. The policy is defined by a set of rules using a rule language described in the usbguard-rules.conf file. The policy and the authorization state of USB devices can be modified during runtime using the USBGuard tool. The system administrator (SA) must work with the site information system security officer (ISSO) to determine a list of authorized peripherals and establish rules within the USBGuard software framework to allow only authorized devices.
SRG-OS-000378-GPOS-00163
1 Rule
AlmaLinux OS 9 must have the USBGuard package enabled.
Medium Severity
The USBGuard-daemon is the main component of the USBGuard software framework. It runs as a service in the background and enforces the USB device authorization policy for all USB devices. The policy is defined by a set of rules using a rule language described in the usbguard-rules.conf file. The policy and the authorization state of USB devices can be modified during runtime using the USBGuard tool. The system administrator (SA) must work with the site information system security officer (ISSO) to determine a list of authorized peripherals and establish rules within the USBGuard software framework to allow only authorized devices.
SRG-OS-000378-GPOS-00163
1 Rule
AlmaLinux OS 9 must block unauthorized peripherals before establishing a connection.
Medium Severity
The USBGuard-daemon is the main component of the USBGuard software framework. It runs as a service in the background and enforces the USB device authorization policy for all USB devices. The policy is defined by a set of rules using a rule language described in the usbguard-rules.conf file. The policy and the authorization state of USB devices can be modified during runtime using the USBGuard tool. The system administrator (SA) must work with the site information system security officer (ISSO) to determine a list of authorized peripherals and establish rules within the USBGuard software framework to allow only authorized devices.
SRG-OS-000379-GPOS-00164
1 Rule
AlmaLinux OS 9 must not have the autofs package installed.
Medium Severity
Without authenticating devices, unidentified or unknown devices may be introduced, thereby facilitating malicious activity. Bidirectional authentication provides stronger safeguards to validate the identity of other devices for connections that are of greater risk. Bidirectional authentication solutions include, but are not limited to, IEEE 802.1x and Extensible Authentication Protocol (EAP), RADIUS server with EAP-Transport Layer Security (TLS) authentication, Kerberos, and SSL mutual authentication. A local connection is any connection with a device communicating without the use of a network. A network connection is any connection with a device that communicates through a network (e.g., local area network, wide area network, or the internet). A remote connection is any connection with a device communicating through an external network (e.g., the internet). Because of the challenges of applying this requirement on a large scale, organizations are encouraged to only apply this requirement to those limited number (and type) of devices that truly need to support this capability. Satisfies: SRG-OS-000379-GPOS-00164, SRG-OS-000114-GPOS-00059
SRG-OS-000118-GPOS-00060
1 Rule
AlmaLinux OS 9 must disable account identifiers (individuals, groups, roles, and devices) after 35 days of inactivity.
Medium Severity
Inactive identifiers pose a risk to systems and applications because attackers may exploit an inactive identifier and potentially obtain undetected access to the system. Automatically disabling inactive accounts ensures that accounts which may not have been responsibly removed are not available to threat actors who may have compromised their credentials. Owners of inactive accounts will not notice if unauthorized access to their user account has been obtained.
SRG-OS-000070-GPOS-00038
1 Rule
AlmaLinux OS 9 must enforce password complexity by requiring that at least one lowercase character be used.
Medium Severity
Use of a complex password helps to increase the time and resources required to compromise the password. Password complexity, or strength, is a measure of the effectiveness of a password in resisting attempts at guessing and brute-force attacks. Password complexity is one factor of several that determines how long it takes to crack a password. The more complex the password, the greater the number of possible combinations that need to be tested before the password is compromised.
SRG-OS-000069-GPOS-00037
1 Rule
AlmaLinux OS 9 must ensure the password complexity module is enabled in the password-auth file.
Medium Severity
Enabling PAM password complexity permits enforcement of strong passwords and consequently makes the system less prone to dictionary attacks.
SRG-OS-000069-GPOS-00037
1 Rule
AlmaLinux OS 9 must ensure the password complexity module in the system-auth file is configured for three retries or less.
Medium Severity
AlmaLinux OS 9 uses "pwquality" as a mechanism to enforce password complexity. This is set in both: /etc/pam.d/password-auth /etc/pam.d/system-auth By limiting the number of attempts to meet the pwquality module complexity requirements before returning with an error, the system will audit abnormal attempts at password changes.
SRG-OS-000069-GPOS-00037
1 Rule
AlmaLinux OS 9 must enforce password complexity rules for the root account.
Medium Severity
Use of a complex password helps to increase the time and resources required to compromise the password. Password complexity, or strength, is a measure of the effectiveness of a password in resisting attempts at guessing and brute-force attacks. Password complexity is one factor of several that determines how long it takes to crack a password. The more complex the password, the greater the number of possible combinations that need to be tested before the password is compromised.
SRG-OS-000069-GPOS-00037
1 Rule
AlmaLinux OS 9 must enforce password complexity by requiring that at least one uppercase character be used.
Medium Severity
Use of a complex password helps to increase the time and resources required to compromise the password. Password complexity, or strength, is a measure of the effectiveness of a password in resisting attempts at guessing and brute-force attacks. Password complexity is one factor of several that determines how long it takes to crack a password. The more complex the password, the greater the number of possible combinations that need to be tested before the password is compromised.
SRG-OS-000266-GPOS-00101
1 Rule
AlmaLinux OS 9 must enforce password complexity by requiring that at least one special character be used.
Medium Severity
Use of a complex password helps to increase the time and resources required to compromise the password. Password complexity, or strength, is a measure of the effectiveness of a password in resisting attempts at guessing and brute-force attacks. Password complexity is one factor of several that determines how long it takes to crack a password. The more complex the password, the greater the number of possible combinations that need to be tested before the password is compromised.
SRG-OS-000078-GPOS-00046
1 Rule
AlmaLinux OS 9 passwords for new users must have a minimum of 15 characters.
Medium Severity
The shorter the password, the lower the number of possible combinations that need to be tested before the password is compromised. Password complexity, or strength, is a measure of the effectiveness of a password in resisting attempts at guessing and brute-force attacks. Password length is one factor of several that helps to determine strength and how long it takes to crack a password. Use of more characters in a password helps to exponentially increase the time and/or resources required to compromise the password. The shorter the password, the lower the number of possible combinations that need to be tested before the password is compromised. Password complexity, or strength, is a measure of the effectiveness of a password in resisting attempts at guessing and brute-force attacks. Password length is one factor of several that helps to determine strength and how long it takes to crack a password. Use of more characters in a password helps to exponentially increase the time and/or resources required to compromise the password.
SRG-OS-000078-GPOS-00046
1 Rule
AlmaLinux OS 9 passwords must be created with a minimum of 15 characters.
Medium Severity
The shorter the password, the lower the number of possible combinations that need to be tested before the password is compromised. Password complexity, or strength, is a measure of the effectiveness of a password in resisting attempts at guessing and brute-force attacks. Password length is one factor of several that helps to determine strength and how long it takes to crack a password. Use of more characters in a password helps to exponentially increase the time and/or resources required to compromise the password. The shorter the password, the lower the number of possible combinations that need to be tested before the password is compromised. Password complexity, or strength, is a measure of the effectiveness of a password in resisting attempts at guessing and brute-force attacks. Password length is one factor of several that helps to determine strength and how long it takes to crack a password. Use of more characters in a password helps to exponentially increase the time and/or resources required to compromise the password. AlmaLinux OS 9 uses the PAM pwquality module as a mechanism to enforce password complexity. Configurations are set in the "/etc/security/pwquality.conf" file or further *.conf files within the "/etc/security/pwquality.conf.d/" directory. The "minlen" parameter acts as a score of complexity based on the credit components of the pwquality module. By setting the credit to a negative value, not only will those components be required, but they will not count toward the total score of minlen. This will result in minlen requiring a 15-character minimum.
SRG-OS-000071-GPOS-00039
1 Rule
AlmaLinux OS 9 must enforce password complexity by requiring that at least one numeric character be used.
Medium Severity
Use of a complex password helps to increase the time and resources required to compromise the password. Password complexity, or strength, is a measure of the effectiveness of a password in resisting attempts at guessing and brute-force attacks. Password complexity is one factor of several that determines how long it takes to crack a password. The more complex the password, the greater the number of possible combinations that need to be tested before the password is compromised.
SRG-OS-000072-GPOS-00040
1 Rule
AlmaLinux OS 9 must require the change of at least four character classes when passwords are changed.
Medium Severity
Use of a complex password helps to increase the time and resources required to compromise the password. Password complexity, or strength, is a measure of the effectiveness of a password in resisting attempts at guessing and brute-force attacks. Password complexity is one factor of several that determines how long it takes to crack a password. The more complex the password, the greater the number of possible combinations that need to be tested before the password is compromised.
SRG-OS-000072-GPOS-00040
1 Rule
AlmaLinux OS 9 must require the maximum number of repeating characters be limited to three when passwords are changed.
Medium Severity
Use of a complex password helps to increase the time and resources required to compromise the password. Password complexity, or strength, is a measure of the effectiveness of a password in resisting attempts at guessing and brute-force attacks. Password complexity is one factor of several that determines how long it takes to crack a password. The more complex the password, the greater the number of possible combinations that need to be tested before the password is compromised.
SRG-OS-000072-GPOS-00040
1 Rule
AlmaLinux OS 9 must require the maximum number of repeating characters of the same character class be limited to four when passwords are changed.
Medium Severity
Use of a complex password helps to increase the time and resources required to compromise the password. Password complexity, or strength, is a measure of the effectiveness of a password in resisting attempts at guessing and brute-force attacks. Password complexity is one factor of several that determines how long it takes to crack a password. The more complex the password, the greater the number of possible combinations that need to be tested before the password is compromised.
SRG-OS-000072-GPOS-00040
1 Rule
AlmaLinux OS 9 must require the change of at least eight characters when passwords are changed.
Medium Severity
Use of a complex password helps to increase the time and resources required to compromise the password. Password complexity, or strength, is a measure of the effectiveness of a password in resisting attempts at guessing and brute-force attacks. Password complexity is one factor of several that determines how long it takes to crack a password. The more complex the password, the greater the number of possible combinations that need to be tested before the password is compromised.
SRG-OS-000073-GPOS-00041
1 Rule
AlmaLinux OS 9 PAM must be configured to use a sufficient number of password hashing rounds.
High Severity
Passwords must be protected at all times, and encryption is the standard method for protecting passwords. If passwords are not encrypted, they can be plainly read (i.e., clear text) and easily compromised. Using more hashing rounds makes password cracking attacks more difficult.
SRG-OS-000073-GPOS-00041
1 Rule
AlmaLinux OS 9 must be configured so that libuser is configured to store only encrypted representations of passwords.
High Severity
Passwords must be protected at all times, and encryption is the standard method for protecting passwords. If passwords are not encrypted, they can be plainly read (i.e., clear text) and easily compromised. The system must use a strong hashing algorithm to store the password.
SRG-OS-000073-GPOS-00041
1 Rule
AlmaLinux OS 9 must be configured so that the system's shadow file is configured to store only encrypted representations of passwords.
High Severity
Passwords must be protected at all times, and encryption is the standard method for protecting passwords. If passwords are not encrypted, they can be plainly read (i.e., clear text) and easily compromised. The system must use a strong hashing algorithm to store the password.
SRG-OS-000073-GPOS-00041
1 Rule
AlmaLinux OS 9 must be configured so that the Pluggable Authentication Module is configured to store only encrypted representations of passwords.
High Severity
Passwords must be protected at all times, and encryption is the standard method for protecting passwords. If passwords are not encrypted, they can be plainly read (i.e., clear text) and easily compromised. The system must use a strong hashing algorithm to store the password.
SRG-OS-000073-GPOS-00041
1 Rule
AlmaLinux OS 9 must be configured so that interactive user account passwords are using strong password hashes.
High Severity
Passwords must be protected at all times, and encryption is the standard method for protecting passwords. If passwords are not encrypted, they can be plainly read (i.e., clear text) and easily compromised. The system must use a strong hashing algorithm to store the password.
SRG-OS-000074-GPOS-00042
1 Rule
AlmaLinux OS 9 must not have any File Transfer Protocol (FTP) packages installed.
High Severity
Passwords must be protected at all times, and encryption is the standard method for protecting passwords. If passwords are not encrypted, they can be plainly read (i.e., clear text) and easily compromised. An FTP server provides an unencrypted file transfer mechanism that does not protect the confidentiality of user credentials or the remote session. If a privileged user were to log on using this service, the privileged user password could be compromised. SFTP or other encrypted file transfer methods must be used instead. Removing the server and client packages prevents inbound and outbound communications from being compromised.
SRG-OS-000074-GPOS-00042
1 Rule
AlmaLinux OS 9 must not have any telnet packages installed.
High Severity
Passwords must be protected at all times, and encryption is the standard method for protecting passwords. If passwords are not encrypted, they can be plainly read (i.e., clear text) and easily compromised. A telnet server provides an unencrypted remote access mechanism that does not protect the confidentiality of user credentials or the remote session. If a privileged user were to log on using this service, the privileged user password could be compromised. SSH or other encrypted session methods must be used instead. Removing the server and client packages prevents inbound and outbound communications from being compromised.
SRG-OS-000076-GPOS-00044
1 Rule
Passwords for existing users must have a 60-day maximum password lifetime restriction in /etc/shadow.
Medium Severity
Any password, no matter how complex, can eventually be cracked. Therefore, Passwords must be changed periodically. If the operating system does not limit the lifetime of passwords and force users to change their passwords, there is the risk that the operating system passwords could be compromised.
SRG-OS-000076-GPOS-00044
1 Rule
Passwords for new users or password changes must have a 60-day maximum password lifetime restriction in /etc/login.defs.
Medium Severity
Any password, no matter how complex, can eventually be cracked. Therefore, passwords must be changed periodically. If the operating system does not limit the lifetime of passwords and force users to change their passwords, there is the risk that the operating system passwords could be compromised.
SRG-OS-000075-GPOS-00043
1 Rule
Passwords for existing users must have a 24-hour minimum password lifetime restriction in /etc/shadow.
Medium Severity
Enforcing a minimum password lifetime helps to prevent repeated password changes to defeat the password reuse or history enforcement requirement. If users are allowed to immediately and continually change their password, then the password could be repeatedly changed in a short period of time to defeat the organization's policy regarding password reuse. Checking existing users have this setting will ensure that no users created before the policy was configured can evade the password minimum setting.
SRG-OS-000075-GPOS-00043
1 Rule
Passwords for new users or password changes must have a 24-hour minimum password lifetime restriction in /etc/login.defs.
Medium Severity
Enforcing a minimum password lifetime helps to prevent repeated password changes to defeat the password reuse or history enforcement requirement. If users are allowed to immediately and continually change their password, then the password could be repeatedly changed in a short period of time to defeat the organization's policy regarding password reuse.
SRG-OS-000383-GPOS-00166
1 Rule
AlmaLinux OS 9 must prohibit the use of cached authenticators after one day.
Medium Severity
Password complexity, or strength, is a measure of the effectiveness of a password in resisting attempts at guessing and brute-force attacks. If the information system or application allows the user to consecutively reuse their password when that password has exceeded its defined lifetime, the end result is a password that is not changed as per policy requirements. If cached authentication information is out-of-date, the validity of the authentication information may be questionable.
SRG-OS-000067-GPOS-00035
1 Rule
For PKI-based authentication, AlmaLinux OS 9 must enforce authorized access to the corresponding private key.
Medium Severity
If the private key is discovered, an attacker can use the key to authenticate as an authorized user and gain access to the network infrastructure. The cornerstone of the PKI is the private key used to encrypt or digitally sign information. If the private key is stolen, this will lead to the compromise of the authentication and nonrepudiation gained through PKI because the attacker can use the private key to digitally sign documents and pretend to be the authorized user. Both the holders of a digital certificate and the issuing authority must protect the computers, storage devices, or whatever they use to keep the private keys.
SRG-OS-000068-GPOS-00036
1 Rule
AlmaLinux OS 9 must map the authenticated identity to the user or group account for PKI-based authentication.
Medium Severity
Without mapping the certificate used to authenticate to the user account, the ability to determine the identity of the individual user or group will not be available for forensic analysis.
SRG-OS-000384-GPOS-00167
1 Rule
AlmaLinux OS 9, for PKI-based authentication, must validate certificates by constructing a certification path (which includes status information) to an accepted trust anchor.
Medium Severity
Without path validation, an informed trust decision by the relying party cannot be made when presented with any certificate not already explicitly trusted. A trust anchor is an authoritative entity represented via a public key and associated data. It is used in the context of public key infrastructures, X.509 digital certificates, and DNSSEC. When there is a chain of trust, usually the top entity to be trusted becomes the trust anchor; it can be, for example, a Certification Authority (CA). A certification path starts with the subject certificate and proceeds through a number of intermediate certificates up to a trusted root certificate, typically issued by a trusted CA. This requirement verifies that a certification path to an accepted trust anchor is used for certificate validation and that the path includes status information. Path validation is necessary for a relying party to make an informed trust decision when presented with any certificate not already explicitly trusted. Status information for certification paths includes certificate revocation lists or online certificate status protocol responses. Validation of the certificate status information is out of scope for this requirement. Satisfies: SRG-OS-000384-GPOS-00167, SRG-OS-000066-GPOS-00034, SRG-OS-000775-GPOS-00230, SRG-OS-000780-GPOS-00240
SRG-OS-000120-GPOS-00061
1 Rule
AlmaLinux OS 9 must use mechanisms meeting the requirements of applicable federal laws, executive orders, directives, policies, regulations, standards, and guidance for authentication to a cryptographic module.
Medium Severity
The key derivation function (KDF) in Kerberos is not FIPS compatible. Overriding the system crypto policy makes the behavior of Kerberos violate expectations, and makes system configuration more fragmented.
SRG-OS-000120-GPOS-00061
1 Rule
AlmaLinux OS 9 must prevent system daemons from using Kerberos for authentication.
Medium Severity
Unapproved mechanisms used for authentication to the cryptographic module are not verified; therefore, cannot be relied upon to provide confidentiality or integrity and DOD data may be compromised. AlmaLinux OS 9 systems using encryption are required to use FIPS-compliant mechanisms for authenticating to cryptographic modules. The key derivation function (KDF) in Kerberos is not FIPS compatible. Ensuring the system does not have any keytab files present prevents system daemons from using Kerberos for authentication. A keytab is a file containing pairs of Kerberos principals and encrypted keys. FIPS 140-3 is the current standard for validating that mechanisms used to access cryptographic modules use authentication that meets DOD requirements. This allows for Security Levels 1, 2, 3, or 4 for use on a general-purpose computing system.
SRG-OS-000120-GPOS-00061
1 Rule
The libreswan package must be installed.
Medium Severity
Providing the ability for remote users or systems to initiate a secure VPN connection protects information when it is transmitted over a wide area network.
SRG-OS-000120-GPOS-00061
1 Rule
AlmaLinux OS 9 must have the packages required for encrypting offloaded audit logs installed.
Medium Severity
The rsyslog-gnutls package provides Transport Layer Security (TLS) support for the rsyslog daemon, which enables secure remote logging.
SRG-OS-000394-GPOS-00174
1 Rule
AlmaLinux OS 9 must have the crypto-policies package installed.
Medium Severity
Centralized cryptographic policies simplify applying secure ciphers across an operating system and the applications that run on that operating system. Use of weak or untested encryption algorithms undermines the purposes of using encryption to protect data. Satisfies: SRG-OS-000394-GPOS-00174, SRG-OS-000393-GPOS-00173
SRG-OS-000394-GPOS-00174
1 Rule
AlmaLinux OS 9 must implement a systemwide encryption policy.
Medium Severity
Centralized cryptographic policies simplify applying secure ciphers across an operating system and the applications that run on that operating system. Use of weak or untested encryption algorithms undermines the purposes of using encryption to protect data. Satisfies: SRG-OS-000394-GPOS-00174, SRG-OS-000396-GPOS-00176
SRG-OS-000395-GPOS-00175
1 Rule
AlmaLinux OS 9 must be configured so that all network connections associated with SSH traffic are terminated after 10 minutes of becoming unresponsive.
Medium Severity
Terminating an unresponsive SSH session within a short time period reduces the window of opportunity for unauthorized personnel to take control of a management session enabled on the console or console port that has been left unattended. In addition, quickly terminating an idle SSH session will also free up resources committed by the managed network element. Terminating network connections associated with communications sessions includes, for example, deallocating associated TCP/IP address/port pairs at the operating system level and deallocating networking assignments at the application level if multiple application sessions are using a single operating system-level network connection. This does not mean the operating system terminates all sessions or network access; it only ends the unresponsive session and releases the resources associated with that session. Satisfies: SRG-OS-000395-GPOS-00175, SRG-OS-000163-GPOS-00072, SRG-OS-000279-GPOS-00109
SRG-OS-000125-GPOS-00065
1 Rule
AlmaLinux OS 9 must enable the Pluggable Authentication Module (PAM) interface for SSHD.
High Severity
When UsePAM is set to "yes", PAM runs through account and session types properly. This is important when restricted access to services based off of IP, time, or other factors of the account is needed. Additionally, this ensures users can inherit certain environment variables on login or disallow access to the server.
SRG-OS-000163-GPOS-00072
1 Rule
AlmaLinux OS 9 must terminate idle user sessions.
Medium Severity
Terminating an idle session within a short time period reduces the window of opportunity for unauthorized personnel to take control of a management session enabled on the console or console port that has been left unattended. In addition, quickly terminating an idle session will also free up resources committed by the managed network element. Terminating network connections associated with communications sessions includes, for example, de-allocating associated TCP/IP address/port pairs at the operating system level, and de-allocating networking assignments at the application level if multiple application sessions are using a single operating system-level network connection. This does not mean that the operating system terminates all sessions or network access; it only ends the inactive session and releases the resources associated with that session.
SRG-OS-000132-GPOS-00067
1 Rule
AlmaLinux OS 9 must disable access to network bpf system call from nonprivileged processes.
Medium Severity
Loading and accessing the packet filters programs and maps using the bpf() system call has the potential of revealing sensitive information about the kernel state.
SRG-OS-000132-GPOS-00067
1 Rule
AlmaLinux OS 9 must restrict exposed kernel pointer addresses access.
Medium Severity
Exposing kernel pointers (through procfs or "seq_printf()") exposes kernel writeable structures, which may contain functions pointers. If a write vulnerability occurs in the kernel, allowing write access to any of this structure, the kernel can be compromised. This option disallows any program without the CAP_SYSLOG capability to get the addresses of kernel pointers by replacing them with "0".
SRG-OS-000132-GPOS-00067
1 Rule
AlmaLinux OS 9 must restrict usage of ptrace to descendant processes.
Medium Severity
Unrestricted usage of ptrace allows compromised binaries to run ptrace on other processes of the user. Like this, the attacker can steal sensitive information from the target processes (e.g. SSH sessions, web browser etc.) without any additional assistance from the user (i.e. without resorting to phishing).
SRG-OS-000132-GPOS-00067
1 Rule
AlmaLinux OS 9 must restrict access to the kernel message buffer.
Medium Severity
Restricting access to the kernel message buffer limits access to only root. This prevents attackers from gaining additional system information as a nonprivileged user. Satisfies: SRG-OS-000132-GPOS-00067, SRG-OS-000138-GPOS-00069
SRG-OS-000132-GPOS-00067
1 Rule
AlmaLinux OS 9 must prevent kernel profiling by nonprivileged users.
Medium Severity
Setting the kernel.perf_event_paranoid kernel parameter to "2" prevents attackers from gaining additional system information as a nonprivileged user. Satisfies: SRG-OS-000132-GPOS-00067, SRG-OS-000138-GPOS-00069
SRG-OS-000403-GPOS-00182
1 Rule
AlmaLinux OS 9 must only allow the use of DOD PKI-established certificate authorities for authentication in the establishment of protected sessions to the operating system.
Medium Severity
Untrusted Certificate Authorities (CA) can issue certificates, but they may be issued by organizations or individuals that seek to compromise DOD systems or by organizations with insufficient security controls. If the CA used for verifying the certificate is not a DOD-approved CA, trust of this CA has not been established. The DOD will only accept PKI-certificates obtained from a DOD-approved internal or external certificate authority. Reliance on CAs for the establishment of secure sessions includes, for example, the use of SSL/TLS certificates.
SRG-OS-000269-GPOS-00103
1 Rule
AlmaLinux OS 9 systemd-journald service must be enabled.
Medium Severity
In the event of a system failure, AlmaLinux OS 9 must preserve any information necessary to determine cause of failure and any information necessary to return to operations with least disruption to system processes.
SRG-OS-000405-GPOS-00184
1 Rule
AlmaLinux OS 9 local disk partitions must implement cryptographic mechanisms to prevent unauthorized disclosure or modification of all information that requires at rest protection.
High Severity
AlmaLinux OS 9 systems handling data requiring "data at rest" protections must employ cryptographic mechanisms to prevent unauthorized disclosure and modification of the information at rest. Selection of a cryptographic mechanism is based on the need to protect the integrity of organizational information. The strength of the mechanism is commensurate with the security category and/or classification of the information. Organizations have the flexibility to either encrypt all information on storage devices (i.e., full disk encryption) or encrypt specific data structures (e.g., files, records, or fields). Satisfies: SRG-OS-000405-GPOS-00184, SRG-OS-000404-GPOS-00183, SRG-OS-000185-GPOS-00079
SRG-OS-000134-GPOS-00068
1 Rule
AlmaLinux OS 9 must use a Linux Security Module configured to enforce limits on system services.
Medium Severity
An isolation boundary provides access control and protects the integrity of the hardware, software, and firmware that perform security functions. Security functions are the hardware, software, and/or firmware of the information system responsible for enforcing the system security policy and supporting the isolation of code and data on which the protection is based. Operating systems implement code separation (i.e., separation of security functions from nonsecurity functions) in a number of ways, including through the provision of security kernels via processor rings or processor modes. For nonkernel code, security function isolation is often achieved through file system protections that serve to protect the code on disk and address space protections that protect executing code. Developers and implementers can increase the assurance in security functions by employing well-defined security policy models; structured, disciplined, and rigorous hardware and software development techniques; and sound system/security engineering principles. Implementation may include isolation of memory space and libraries. Operating systems restrict access to security functions through the use of access control mechanisms and by implementing least privilege capabilities.
SRG-OS-000134-GPOS-00068
1 Rule
AlmaLinux OS 9 must have the policycoreutils package installed.
Medium Severity
Policycoreutils contains the policy core utilities that are required for basic operation of an SELinux-enabled system. These utilities include load_policy to load SELinux policies, setfile to label filesystems, newrole to switch roles, and run_init to run /etc/init.d scripts in the proper context.
SRG-OS-000138-GPOS-00069
1 Rule
Any AlmaLinux OS 9 world-writable directories must be owned by root, sys, bin, or an application user.
Medium Severity
If a world-writable directory is not owned by root, sys, bin, or an application user identifier (UID), unauthorized users may be able to modify files created by others. The only authorized public directories are those temporary directories supplied with the system or those designed to be temporary file repositories. The setting is normally reserved for directories used by the system and by users for temporary file storage, (e.g., /tmp), and for directories requiring global read/write access.
SRG-OS-000138-GPOS-00069
1 Rule
A sticky bit must be set on all AlmaLinux OS 9 public directories.
Medium Severity
Preventing unauthorized information transfers mitigates the risk of information, including encrypted representations of information, produced by the actions of prior users/roles (or the actions of processes acting on behalf of prior users/roles) from being available to any current users/roles (or current processes) that obtain access to shared system resources (e.g., registers, main memory, hard disks) after those resources have been released back to information systems. The control of information in shared resources is also commonly referred to as object reuse and residual information protection. This requirement generally applies to the design of an information technology product, but it can also apply to the configuration of particular information system components that are, or use, such products. This can be verified by acceptance/validation processes in DOD or other government agencies. There may be shared resources with configurable protections (e.g., files in storage) that may be assessed on specific information system components.
SRG-OS-000420-GPOS-00186
1 Rule
AlmaLinux OS 9 must protect against or limit the effects of denial-of-service (DoS) attacks by ensuring rate-limiting measures on impacted network interfaces are implemented.
Medium Severity
DoS is a condition when a resource is not available for legitimate users. When this occurs, the organization either cannot accomplish its mission or must operate at degraded capacity. This requirement addresses the configuration of the operating system to mitigate the impact of DoS attacks that have occurred or are ongoing on system availability. For each system, known and potential DoS attacks must be identified and solutions for each type implemented. A variety of technologies exist to limit or, in some cases, eliminate the effects of DoS attacks (e.g., limiting processes or establishing memory partitions). Employing increased capacity and bandwidth, combined with service redundancy, may reduce the susceptibility to some DoS attacks.
SRG-OS-000420-GPOS-00186
1 Rule
AlmaLinux OS 9 must be configured to use TCP syncookies.
Medium Severity
Denial of Service (DoS) is a condition when a resource is not available for legitimate users. When this occurs, the organization either cannot accomplish its mission or must operate at degraded capacity. This requirement addresses the configuration of the operating system to mitigate the impact of DoS attacks that have occurred or are ongoing on system availability. For each system, known and potential DoS attacks must be identified and solutions for each type implemented. A variety of technologies exist to limit or, in some cases, eliminate the effects of DoS attacks (e.g., limiting processes or establishing memory partitions). Employing increased capacity and bandwidth, combined with service redundancy, may reduce the susceptibility to some DoS attacks. Satisfies: SRG-OS-000420-GPOS-00186, SRG-OS-000142-GPOS-00071
SRG-OS-000423-GPOS-00187
1 Rule
All AlmaLinux OS 9 networked systems must have the OpenSSH client installed.
High Severity
Without protection of the transmitted information, confidentiality and integrity may be compromised because unprotected communications can be intercepted and either read or altered. This requirement applies to both internal and external networks and all types of information system components from which information can be transmitted (e.g., servers, mobile devices, notebook computers, printers, copiers, scanners, and facsimile machines). Communication paths outside the physical protection of a controlled boundary are exposed to the possibility of interception and modification. Protecting the confidentiality and integrity of organizational information can be accomplished by physical means (e.g., employing physical distribution systems) or by logical means (e.g., employing cryptographic techniques). If physical means of protection are employed, then logical means (cryptography) do not have to be employed, and vice versa.
SRG-OS-000424-GPOS-00188
1 Rule
All AlmaLinux OS 9 networked systems must implement SSH to protect the confidentiality and integrity of transmitted and received information, including information being prepared for transmission.
Medium Severity
Without protection of the transmitted information, confidentiality and integrity may be compromised because unprotected communications can be intercepted and either read or altered. This requirement applies to both internal and external networks and all types of information system components from which information can be transmitted (e.g., servers, mobile devices, notebook computers, printers, copiers, scanners, and facsimile machines). Communication paths outside the physical protection of a controlled boundary are exposed to the possibility of interception and modification. Protecting the confidentiality and integrity of organizational information can be accomplished by physical means (e.g., employing physical distribution systems) or by logical means (e.g., employing cryptographic techniques). If physical means of protection are employed, then logical means (cryptography) do not have to be employed, and vice versa. Satisfies: SRG-OS-000424-GPOS-00188, SRG-OS-000426-GPOS-00190
SRG-OS-000424-GPOS-00188
1 Rule
All AlmaLinux OS 9 networked systems must have the OpenSSH server installed.
Medium Severity
Without protection of the transmitted information, confidentiality and integrity may be compromised because unprotected communications can be intercepted and either read or altered. This requirement applies to both internal and external networks and all types of information system components from which information can be transmitted (e.g., servers, mobile devices, notebook computers, printers, copiers, scanners, and facsimile machines). Communication paths outside the physical protection of a controlled boundary are exposed to the possibility of interception and modification. Protecting the confidentiality and integrity of organizational information can be accomplished by physical means (e.g., employing physical distribution systems) or by logical means (e.g., employing cryptographic techniques). If physical means of protection are employed, then logical means (cryptography) do not have to be employed, and vice versa. Satisfies: SRG-OS-000424-GPOS-00188, SRG-OS-000426-GPOS-00190
SRG-OS-000425-GPOS-00189
1 Rule
AlmaLinux OS 9 must not allow users to override SSH environment variables.
Medium Severity
SSH environment options potentially allow users to bypass access restriction in some configurations.
SRG-OS-000426-GPOS-00190
1 Rule
AlmaLinux OS 9 must implement DOD-approved encryption in the bind package.
Medium Severity
Without cryptographic integrity protections, information can be altered by unauthorized users without detection. Cryptographic mechanisms used for protecting the integrity of information include, for example, signed hash functions using asymmetric cryptography enabling distribution of the public key to verify the hash information while maintaining the confidentiality of the secret key used to generate the hash. AlmaLinux OS 9 incorporates systemwide crypto policies by default. The employed algorithms can be viewed in the /etc/crypto-policies/back-ends/ directory.
SRG-OS-000481-GPOS-00481
1 Rule
AlmaLinux OS 9 wireless network adapters must be disabled.
Medium Severity
This requirement applies to wireless peripheral technologies (e.g., wireless mice, keyboards, displays, etc.) used with AlmaLinux OS 9 systems. Wireless peripherals (e.g., Wi-Fi/Bluetooth/IR keyboards, mice and pointing devices, and near field communications [NFC]) present a unique challenge by creating an open, unsecured port on a computer. Wireless peripherals must meet DOD requirements for wireless data transmission and be approved for use by the authorizing official (AO). Even though some wireless peripherals, such as mice and pointing devices, do not ordinarily carry information that need to be protected, modification of communications with these wireless peripherals may be used to compromise the AlmaLinux OS 9 operating system. Satisfies: SRG-OS-000481-GPOS-00481, SRG-OS-000299-GPOS-00117, SRG-OS-000300-GPOS-00118
SRG-OS-000206-GPOS-00084
1 Rule
AlmaLinux OS 9 must not show boot up messages.
Medium Severity
Only authorized personnel should be aware of errors and the details of the errors. Error messages are an indicator of an organization's operational state or can identify the AlmaLinux OS 9 system or platform. Additionally, personally identifiable information (PII) and operational information must not be revealed through error messages to unauthorized personnel or their designated representatives. The structure and content of error messages must be carefully considered by the organization and development team. The extent to which the information system is able to identify and handle error conditions is guided by organizational policy and operational requirements.
SRG-OS-000206-GPOS-00084
1 Rule
AlmaLinux OS 9 /var/log directory must be group-owned by root.
Medium Severity
Only authorized personnel should be aware of errors and the details of the errors. Error messages are an indicator of an organization's operational state or can identify the AlmaLinux OS 9 system or platform. Additionally, personally identifiable information (PII) and operational information must not be revealed through error messages to unauthorized personnel or their designated representatives. The structure and content of error messages must be carefully considered by the organization and development team. The extent to which the information system is able to identify and handle error conditions is guided by organizational policy and operational requirements.
SRG-OS-000206-GPOS-00084
1 Rule
AlmaLinux OS 9 /var/log/messages file must be group-owned by root.
Medium Severity
Only authorized personnel should be aware of errors and the details of the errors. Error messages are an indicator of an organization's operational state or can identify the AlmaLinux OS 9 system or platform. Additionally, personally identifiable information (PII) and operational information must not be revealed through error messages to unauthorized personnel or their designated representatives. The structure and content of error messages must be carefully considered by the organization and development team. The extent to which the information system is able to identify and handle error conditions is guided by organizational policy and operational requirements.
SRG-OS-000206-GPOS-00084
1 Rule
AlmaLinux OS 9 /var/log/messages file must be owned by root.
Medium Severity
Only authorized personnel should be aware of errors and the details of the errors. Error messages are an indicator of an organization's operational state or can identify the AlmaLinux OS 9 system or platform. Additionally, personally identifiable information (PII) and operational information must not be revealed through error messages to unauthorized personnel or their designated representatives. The structure and content of error messages must be carefully considered by the organization and development team. The extent to which the information system is able to identify and handle error conditions is guided by organizational policy and operational requirements.
SRG-OS-000206-GPOS-00084
1 Rule
AlmaLinux OS 9 /var/log/messages file must have mode 0640 or less permissive.
Medium Severity
Only authorized personnel should be aware of errors and the details of the errors. Error messages are an indicator of an organization's operational state or can identify the AlmaLinux OS 9 system or platform. Additionally, personally identifiable information (PII) and operational information must not be revealed through error messages to unauthorized personnel or their designated representatives. The structure and content of error messages must be carefully considered by the organization and development team. The extent to which the information system is able to identify and handle error conditions is guided by organizational policy and operational requirements.
SRG-OS-000206-GPOS-00084
1 Rule
AlmaLinux OS 9 /var/log directory must be owned by root.
Medium Severity
Only authorized personnel should be aware of errors and the details of the errors. Error messages are an indicator of an organization's operational state or can identify the AlmaLinux OS 9 system or platform. Additionally, personally identifiable information (PII) and operational information must not be revealed through error messages to unauthorized personnel or their designated representatives. The structure and content of error messages must be carefully considered by the organization and development team. The extent to which the information system is able to identify and handle error conditions is guided by organizational policy and operational requirements.
SRG-OS-000206-GPOS-00084
1 Rule
AlmaLinux OS 9 /var/log directory must have mode 0755 or less permissive.
Medium Severity
Only authorized personnel should be aware of errors and the details of the errors. Error messages are an indicator of an organization's operational state or can identify the AlmaLinux OS 9 system or platform. Additionally, personally identifiable information (PII) and operational information must not be revealed through error messages to unauthorized personnel or their designated representatives. The structure and content of error messages must be carefully considered by the organization and development team. The extent to which the information system is able to identify and handle error conditions is guided by organizational policy and operational requirements.
SRG-OS-000433-GPOS-00192
1 Rule
AlmaLinux OS 9 must implement nonexecutable data to protect its memory from unauthorized code execution.
Medium Severity
ExecShield uses the segmentation feature on all x86 systems to prevent execution in memory higher than a certain address. It writes an address as a limit in the code segment descriptor, to control where code can be executed, on a per-process basis. When the kernel places the memory regions of a process, such as the stack and heap, higher than this address, the hardware prevents execution in that address range.
SRG-OS-000433-GPOS-00192
1 Rule
AlmaLinux OS 9 must enable mitigations against processor-based vulnerabilities.
Medium Severity
Kernel page-table isolation is a kernel feature that mitigates the Meltdown security vulnerability and hardens the kernel against attempts to bypass kernel address space layout randomization (KASLR).
SRG-OS-000433-GPOS-00192
1 Rule
AlmaLinux OS 9 must clear SLUB/SLAB objects to prevent use-after-free attacks.
Medium Severity
Poisoning writes an arbitrary value to freed pages, so any modification or reference to that page after being freed or before being initialized will be detected and prevented. This prevents many types of use-after-free vulnerabilities at some performance cost. Also prevents leak of data and detection of corrupted memory. SLAB objects are blocks of physically contiguous memory. SLUB is the unqueued SLAB allocator.
SRG-OS-000433-GPOS-00193
1 Rule
AlmaLinux OS 9 must implement address space layout randomization (ASLR) to protect its memory from unauthorized code execution.
Medium Severity
ASLR makes it more difficult for an attacker to predict the location of attack code they have introduced into a process' address space during an attempt at exploitation. Additionally, ASLR makes it more difficult for an attacker to know the location of existing code to repurpose it using return oriented programming (ROP) techniques.
SRG-OS-000437-GPOS-00194
1 Rule
AlmaLinux OS 9 must remove all software components after updated versions have been installed.
Medium Severity
Previous versions of software components that are not removed from the information system after updates have been installed may be exploited by some adversaries.
SRG-OS-000439-GPOS-00195
1 Rule
AlmaLinux OS 9 must be a supported release.
High Severity
Security flaws with operating systems are discovered daily. Vendors are constantly updating and patching their products to address newly discovered security vulnerabilities. Organizations (including any contractor to the organization) are required to promptly install security-relevant software updates (e.g., patches, service packs, and hot fixes). Flaws discovered during security assessments, continuous monitoring, incident response activities, or information system error handling must also be addressed expeditiously.
SRG-OS-000445-GPOS-00199
1 Rule
AlmaLinux OS 9 must enable the SELinux targeted policy.
Medium Severity
Setting the SELinux policy to "targeted" or a more specialized policy ensures the system will confine processes that are likely to be targeted for exploitation, such as network or system services. Note: During the development or debugging of SELinux modules, it is common to temporarily place nonproduction systems in "permissive" mode. In such temporary cases, SELinux policies should be developed, and once work is completed, the system should be reconfigured to "targeted".
SRG-OS-000445-GPOS-00199
1 Rule
AlmaLinux OS 9 must have the Advanced Intrusion Detection Environment (AIDE) package installed.
Medium Severity
Without verification of the security functions, security functions may not operate correctly and the failure may go unnoticed. Security function is defined as the hardware, software, and/or firmware of the information system responsible for enforcing the system security policy and supporting the isolation of code and data on which the protection is based. Security functionality includes, but is not limited to, establishing system accounts, configuring access authorizations (i.e., permissions, privileges), setting events to be audited, and setting intrusion detection parameters. This requirement applies to operating systems performing security function verification/testing and/or systems and environments that require this functionality. Satisfies: SRG-OS-000445-GPOS-00199, SRG-OS-000446-GPOS-00200, SRG-OS-000363-GPOS-00150
SRG-OS-000447-GPOS-00201
1 Rule
AlmaLinux OS 9 must routinely check the baseline configuration for unauthorized changes and notify the system administrator when anomalies in the operation of any security functions are discovered.
Medium Severity
Unauthorized changes to the baseline configuration could make the system vulnerable to various attacks or allow unauthorized access to the operating system. Changes to operating system configurations can have unintended side effects, some of which may be relevant to security. Detecting such changes and providing an automated response can help avoid unintended, negative consequences that could ultimately affect the security state of the operating system. The operating system's information management officer (IMO)/information system security officer (ISSO) and system administrators (SAs) must be notified via email and/or monitoring system trap when there is an unauthorized modification of a configuration item. Notifications provided by information systems include messages to local computer consoles, and/or hardware indications, such as lights. This capability must take into account operational requirements for availability for selecting an appropriate response. The organization may choose to shut down or restart the information system upon security function anomaly detection. Satisfies: SRG-OS-000447-GPOS-00201, SRG-OS-000446-GPOS-00200, SRG-OS-000363-GPOS-00150
SRG-OS-000062-GPOS-00031
1 Rule
AlmaLinux OS 9 audit system must audit local events.
Medium Severity
Without establishing what type of events occurred, the source of events, where events occurred, and the outcome of events, it would be difficult to establish, correlate, and investigate the events leading up to an outage or attack. If option "local_events" is not set to "yes", only events from network will be aggregated.
SRG-OS-000063-GPOS-00032
1 Rule
AlmaLinux OS 9 /etc/audit/auditd.conf file must have 0640 or less permissive to prevent unauthorized access.
Medium Severity
Without the capability to restrict which roles and individuals can select which events are audited, unauthorized personnel may be able to prevent the auditing of critical events. Misconfigured audits may degrade the system's performance by overwhelming the audit log. Misconfigured audits may also make it more difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one.
SRG-OS-000063-GPOS-00032
1 Rule
AlmaLinux OS 9 must allow only the information system security manager (ISSM) (or individuals or roles appointed by the ISSM) to select which auditable events are to be audited.
Medium Severity
Without the capability to restrict which roles and individuals can select which events are audited, unauthorized personnel may be able to prevent the auditing of critical events. Misconfigured audits may degrade the system's performance by overwhelming the audit log. Misconfigured audits may also make it more difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one.
SRG-OS-000477-GPOS-00222
1 Rule
Successful/unsuccessful uses of the init command in AlmaLinux OS 9 must generate an audit record.
Medium Severity
Without generating audit records specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). When a user logs on, the auid is set to the uid of the account being authenticated. Daemons are not user sessions and have the loginuid set to -1. The auid representation is an unsigned 32-bit integer, which equals 4294967295. The audit system interprets -1, 4294967295, and "unset" in the same way. The system call rules are loaded into a matching engine that intercepts each system call made by all programs on the system. Therefore, it is very important to use system call rules only when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. The performance can be helped, however, by combining system calls into one rule whenever possible. Satisfies: SRG-OS-000477-GPOS-00222, SRG-OS-000471-GPOS-00215
SRG-OS-000477-GPOS-00222
1 Rule
AlmaLinux OS 9 must generate audit records for any use of the "poweroff" command.
Medium Severity
Without generating audit records specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). When a user logs on, the auid is set to the uid of the account being authenticated. Daemons are not user sessions and have the loginuid set to -1. The auid representation is an unsigned 32-bit integer, which equals 4294967295. The audit system interprets -1, 4294967295, and "unset" in the same way. The system call rules are loaded into a matching engine that intercepts each system call made by all programs on the system. Therefore, it is very important to use system call rules only when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. The performance can be helped, however, by combining system calls into one rule whenever possible. Satisfies: SRG-OS-000477-GPOS-00222, SRG-OS-000471-GPOS-00215
SRG-OS-000477-GPOS-00222
1 Rule
AlmaLinux OS 9 must generate audit records for any use of the "reboot" command.
Medium Severity
Without generating audit records specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). When a user logs on, the auid is set to the uid of the account being authenticated. Daemons are not user sessions and have the loginuid set to -1. The auid representation is an unsigned 32-bit integer, which equals 4294967295. The audit system interprets -1, 4294967295, and "unset" in the same way. The system call rules are loaded into a matching engine that intercepts each system call made by all programs on the system. Therefore, it is very important to use system call rules only when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. The performance can be helped, however, by combining system calls into one rule whenever possible. Satisfies: SRG-OS-000477-GPOS-00222, SRG-OS-000471-GPOS-00215
SRG-OS-000477-GPOS-00222
1 Rule
AlmaLinux must generate audit records for any use of the "shutdown" command.
Medium Severity
Without generating audit records specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). When a user logs on, the auid is set to the uid of the account being authenticated. Daemons are not user sessions and have the loginuid set to -1. The auid representation is an unsigned 32-bit integer, which equals 4294967295. The audit system interprets -1, 4294967295, and "unset" in the same way. The system call rules are loaded into a matching engine that intercepts each system call made by all programs on the system. Therefore, it is very important to use system call rules only when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. The performance can be helped, however, by combining system calls into one rule whenever possible. Satisfies: SRG-OS-000477-GPOS-00222, SRG-OS-000471-GPOS-00215
SRG-OS-000477-GPOS-00222
1 Rule
AlmaLinux OS 9 must enable Linux audit logging for the USBGuard daemon.
Medium Severity
Without generating audit records specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). When a user logs on, the auid is set to the uid of the account being authenticated. Daemons are not user sessions and have the loginuid set to -1. The auid representation is an unsigned 32-bit integer, which equals 4294967295. The audit system interprets -1, 4294967295, and "unset" in the same way. The system call rules are loaded into a matching engine that intercepts each system call made by all programs on the system. Therefore, it is very important to use system call rules only when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. The performance can be helped, however, by combining system calls into one rule whenever possible.
SRG-OS-000477-GPOS-00222
1 Rule
AlmaLinux OS 9 must audit all uses of the delete_module, init_module and finit_module system calls.
Medium Severity
Without generating audit records specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). When a user logs on, the auid is set to the uid of the account being authenticated. Daemons are not user sessions and have the loginuid set to -1. The auid representation is an unsigned 32-bit integer, which equals 4294967295. The audit system interprets -1, 4294967295, and "unset" in the same way. The system call rules are loaded into a matching engine that intercepts each system call made by all programs on the system. Therefore, it is very important to use system call rules only when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. The performance can be helped, however, by combining system calls into one rule whenever possible. Satisfies: SRG-OS-000477-GPOS-00222, SRG-OS-000471-GPOS-00216
SRG-OS-000392-GPOS-00172
1 Rule
AlmaLinux OS 9 must generate audit records for all account creations, modifications, disabling, and termination events that affect /var/log/tallylog.
Medium Severity
Without generating audit records specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). When a user logs on, the auid is set to the uid of the account being authenticated. Daemons are not user sessions and have the loginuid set to -1. The auid representation is an unsigned 32-bit integer, which equals 4294967295. The audit system interprets -1, 4294967295, and "unset" in the same way. The system call rules are loaded into a matching engine that intercepts each system call made by all programs on the system. Therefore, it is very important to use system call rules only when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. The performance can be helped, however, by combining system calls into one rule whenever possible. Satisfies: SRG-OS-000392-GPOS-00172, SRG-OS-000470-GPOS-00214, SRG-OS-000473-GPOS-00218
SRG-OS-000255-GPOS-00096
1 Rule
AlmaLinux OS 9 must produce audit records containing information to establish the identity of any individual or process associated with the event.
Medium Severity
Without information that establishes the identity of the subjects (i.e., users or processes acting on behalf of users) associated with the events, security personnel cannot determine responsibility for the potentially harmful event.
SRG-OS-000037-GPOS-00015
1 Rule
The audit package must be installed on AlmaLinux OS 9.
Medium Severity
Without establishing what type of events occurred, the source of events, where events occurred, and the outcome of events, it would be difficult to establish, correlate, and investigate the events leading up to an outage or attack. Audit record content that may be necessary to satisfy this requirement includes, for example, time stamps, source and destination addresses, user/process identifiers, event descriptions, success/fail indications, filenames involved, and access control or flow control rules invoked. Associating event types with detected events in audit logs provides a means of investigating an attack, recognizing resource usage or capacity thresholds, or identifying an improperly configured AlmaLinux OS 9 system. Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000038-GPOS-00016, SRG-OS-000039-GPOS-00017, SRG-OS-000040-GPOS-00018, SRG-OS-000041-GPOS-00019, SRG-OS-000042-GPOS-00020, SRG-OS-000042-GPOS-00021, SRG-OS-000051-GPOS-00024, SRG-OS-000392-GPOS-00172, SRG-OS-000473-GPOS-00218, SRG-OS-000472-GPOS-00217, SRG-OS-000474-GPOS-00219, SRG-OS-000365-GPOS-00152, SRG-OS-000358-GPOS-00145, SRG-OS-000348-GPOS-00136, SRG-OS-000349-GPOS-00137, SRG-OS-000350-GPOS-00138, SRG-OS-000351-GPOS-00139, SRG-OS-000352-GPOS-00140, SRG-OS-000353-GPOS-00141, SRG-OS-000354-GPOS-00142, SRG-OS-000337-GPOS-00129, SRG-OS-000062-GPOS-00031, SRG-OS-000054-GPOS-00025
SRG-OS-000037-GPOS-00015
1 Rule
AlmaLinux OS 9 must generate audit records for all account creations, modifications, disabling, and termination events that affect /var/log/lastlog.
Medium Severity
Without generating audit records specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). When a user logs on, the auid is set to the uid of the account being authenticated. Daemons are not user sessions and have the loginuid set to -1. The auid representation is an unsigned 32-bit integer, which equals 4294967295. The audit system interprets -1, 4294967295, and "unset" in the same way. The system call rules are loaded into a matching engine that intercepts each system call made by all programs on the system. Therefore, it is very important to use system call rules only when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. The performance can be helped, however, by combining system calls into one rule whenever possible. Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215, SRG-OS-000473-GPOS-00218, SRG-OS-000470-GPOS-00214
SRG-OS-000037-GPOS-00015
1 Rule
AlmaLinux OS 9 must generate audit records for any use of the "mount" command.
Medium Severity
Without generating audit records specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). When a user logs on, the auid is set to the uid of the account being authenticated. Daemons are not user sessions and have the loginuid set to -1. The auid representation is an unsigned 32-bit integer, which equals 4294967295. The audit system interprets -1, 4294967295, and "unset" in the same way. The system call rules are loaded into a matching engine that intercepts each system call made by all programs on the system. Therefore, it is very important to use system call rules only when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. The performance can be helped, however, by combining system calls into one rule whenever possible. Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215
SRG-OS-000037-GPOS-00015
1 Rule
AlmaLinux OS 9 must generate audit records for any use of the "umount" command.
Medium Severity
Without generating audit records specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). When a user logs on, the auid is set to the uid of the account being authenticated. Daemons are not user sessions and have the loginuid set to -1. The auid representation is an unsigned 32-bit integer, which equals 4294967295. The audit system interprets -1, 4294967295, and "unset" in the same way. The system call rules are loaded into a matching engine that intercepts each system call made by all programs on the system. Therefore, it is very important to use system call rules only when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. The performance can be helped, however, by combining system calls into one rule whenever possible. Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215
SRG-OS-000037-GPOS-00015
1 Rule
Successful/unsuccessful uses of the umount2 system call in AlmaLinux OS 9 must generate an audit record.
Medium Severity
Without generating audit records specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). When a user logs on, the auid is set to the uid of the account being authenticated. Daemons are not user sessions and have the loginuid set to -1. The auid representation is an unsigned 32-bit integer, which equals 4294967295. The audit system interprets -1, 4294967295, and "unset" in the same way. The system call rules are loaded into a matching engine that intercepts each system call made by all programs on the system. Therefore, it is very important to use system call rules only when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. The performance can be helped, however, by combining system calls into one rule whenever possible. Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215
SRG-OS-000037-GPOS-00015
1 Rule
AlmaLinux OS 9 must enable auditing of processes that start prior to the audit daemon.
Medium Severity
Without the capability to generate audit records, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. If auditing is enabled late in the startup process, the actions of some startup processes may not be audited. Some audit systems also maintain state information only available if auditing is enabled before a given process is created. Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215, SRG-OS-000473-GPOS-00218, SRG-OS-000254-GPOS-00095
SRG-OS-000037-GPOS-00015
1 Rule
AlmaLinux OS 9 must audit all uses of the truncate, ftruncate, creat, open, openat, and open_by_handle_at system calls.
Medium Severity
Without generating audit records specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). When a user logs on, the auid is set to the uid of the account being authenticated. Daemons are not user sessions and have the loginuid set to -1. The auid representation is an unsigned 32-bit integer, which equals 4294967295. The audit system interprets -1, 4294967295, and "unset" in the same way. The system call rules are loaded into a matching engine that intercepts each system call made by all programs on the system. Therefore, it is very important to use system call rules only when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. The performance can be helped, however, by combining system calls into one rule whenever possible. Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215, SRG-OS-000064-GPOS-00033, SRG-OS-000458-GPOS-00203, SRG-OS-000461-GPOS-00205
SRG-OS-000037-GPOS-00015
1 Rule
AlmaLinux OS 9 must generate audit records for any use of the "chacl" command.
Medium Severity
Without generating audit records specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). When a user logs on, the auid is set to the uid of the account being authenticated. Daemons are not user sessions and have the loginuid set to -1. The auid representation is an unsigned 32-bit integer, which equals 4294967295. The audit system interprets -1, 4294967295, and "unset" in the same way. The system call rules are loaded into a matching engine that intercepts each system call made by all programs on the system. Therefore, it is very important to use system call rules only when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. The performance can be helped, however, by combining system calls into one rule whenever possible. Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215, SRG-OS-000466-GPOS-00210
SRG-OS-000037-GPOS-00015
1 Rule
AlmaLinux OS 9 must generate audit records for any use of the "chage" command.
Medium Severity
Without generating audit records specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). When a user logs on, the auid is set to the uid of the account being authenticated. Daemons are not user sessions and have the loginuid set to -1. The auid representation is an unsigned 32-bit integer, which equals 4294967295. The audit system interprets -1, 4294967295, and "unset" in the same way. The system call rules are loaded into a matching engine that intercepts each system call made by all programs on the system. Therefore, it is very important to use system call rules only when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. The performance can be helped, however, by combining system calls into one rule whenever possible. Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000468-GPOS-00212, SRG-OS-000471-GPOS-00215
SRG-OS-000037-GPOS-00015
1 Rule
AlmaLinux OS 9 must generate audit records for any use of the "chcon" command.
Medium Severity
Without generating audit records specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). When a user logs on, the auid is set to the uid of the account being authenticated. Daemons are not user sessions and have the loginuid set to -1. The auid representation is an unsigned 32-bit integer, which equals 4294967295. The audit system interprets -1, 4294967295, and "unset" in the same way. The system call rules are loaded into a matching engine that intercepts each system call made by all programs on the system. Therefore, it is very important to use system call rules only when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. The performance can be helped, however, by combining system calls into one rule whenever possible. Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000468-GPOS-00212, SRG-OS-000471-GPOS-00215, SRG-OS-000463-GPOS-00207, SRG-OS-000465-GPOS-00209
SRG-OS-000037-GPOS-00015
1 Rule
AlmaLinux OS 9 must audit all uses of the chmod, fchmod, and fchmodat system calls.
Medium Severity
Without generating audit records specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). When a user logs on, the auid is set to the uid of the account being authenticated. Daemons are not user sessions and have the loginuid set to -1. The auid representation is an unsigned 32-bit integer, which equals 4294967295. The audit system interprets -1, 4294967295, and "unset" in the same way. The system call rules are loaded into a matching engine that intercepts each system call made by all programs on the system. Therefore, it is very important to use system call rules only when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. The performance can be helped, however, by combining system calls into one rule whenever possible. Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215, SRG-OS-000064-GPOS-00033, SRG-OS-000466-GPOS-00210, SRG-OS-000458-GPOS-00203
SRG-OS-000037-GPOS-00015
1 Rule
AlmaLinux OS 9 must audit all uses of the chown, fchown, fchownat, and lchown system calls.
Medium Severity
Without generating audit records specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). When a user logs on, the auid is set to the uid of the account being authenticated. Daemons are not user sessions and have the loginuid set to -1. The auid representation is an unsigned 32-bit integer, which equals 4294967295. The audit system interprets -1, 4294967295, and "unset" in the same way. The system call rules are loaded into a matching engine that intercepts each system call made by all programs on the system. Therefore, it is very important to use system call rules only when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. The performance can be helped, however, by combining system calls into one rule whenever possible. Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215, SRG-OS-000064-GPOS-00033, SRG-OS-000466-GPOS-00210, SRG-OS-000458-GPOS-00203, SRG-OS-000474-GPOS-00219
SRG-OS-000037-GPOS-00015
1 Rule
AlmaLinux OS 9 must generate audit records for any use of the "chsh" command.
Medium Severity
Without generating audit records specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). When a user logs on, the auid is set to the uid of the account being authenticated. Daemons are not user sessions and have the loginuid set to -1. The auid representation is an unsigned 32-bit integer, which equals 4294967295. The audit system interprets -1, 4294967295, and "unset" in the same way. The system call rules are loaded into a matching engine that intercepts each system call made by all programs on the system. Therefore, it is very important to use system call rules only when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. The performance can be helped, however, by combining system calls into one rule whenever possible. Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215
SRG-OS-000037-GPOS-00015
1 Rule
AlmaLinux OS 9 must generate audit records for any use of the "crontab" command.
Medium Severity
Without generating audit records specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). When a user logs on, the auid is set to the uid of the account being authenticated. Daemons are not user sessions and have the loginuid set to -1. The auid representation is an unsigned 32-bit integer, which equals 4294967295. The audit system interprets -1, 4294967295, and "unset" in the same way. The system call rules are loaded into a matching engine that intercepts each system call made by all programs on the system. Therefore, it is very important to use system call rules only when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. The performance can be helped, however, by combining system calls into one rule whenever possible. Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215
SRG-OS-000037-GPOS-00015
1 Rule
AlmaLinux OS 9 must audit all uses of the rename, unlink, rmdir, renameat, and unlinkat system calls.
Medium Severity
Without generating audit records specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). When a user logs on, the auid is set to the uid of the account being authenticated. Daemons are not user sessions and have the loginuid set to -1. The auid representation is an unsigned 32-bit integer, which equals 4294967295. The audit system interprets -1, 4294967295, and "unset" in the same way. The system call rules are loaded into a matching engine that intercepts each system call made by all programs on the system. Therefore, it is very important to use system call rules only when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. The performance can be helped, however, by combining system calls into one rule whenever possible. Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215, SRG-OS-000466-GPOS-00210, SRG-OS-000467-GPOS-00211, SRG-OS-000468-GPOS-00212
SRG-OS-000477-GPOS-00222
1 Rule
AlmaLinux OS 9 must generate audit records for all account creations, modifications, disabling, and termination events that affect /var/log/faillock.
Medium Severity
Without generating audit records specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). When a user logs on, the auid is set to the uid of the account being authenticated. Daemons are not user sessions and have the loginuid set to -1. The auid representation is an unsigned 32-bit integer, which equals 4294967295. The audit system interprets -1, 4294967295, and "unset" in the same way. The system call rules are loaded into a matching engine that intercepts each system call made by all programs on the system. Therefore, it is very important to use system call rules only when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. The performance can be helped, however, by combining system calls into one rule whenever possible. Satisfies: SRG-OS-000477-GPOS-00222, SRG-OS-000476-GPOS-00221, SRG-OS-000475-GPOS-00220
SRG-OS-000037-GPOS-00015
1 Rule
AlmaLinux OS 9 must generate audit records for any use of the "gpasswd" command.
Medium Severity
Without generating audit records specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). When a user logs on, the auid is set to the uid of the account being authenticated. Daemons are not user sessions and have the loginuid set to -1. The auid representation is an unsigned 32-bit integer, which equals 4294967295. The audit system interprets -1, 4294967295, and "unset" in the same way. The system call rules are loaded into a matching engine that intercepts each system call made by all programs on the system. Therefore, it is very important to use system call rules only when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. The performance can be helped, however, by combining system calls into one rule whenever possible. Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215
SRG-OS-000037-GPOS-00015
1 Rule
AlmaLinux OS 9 must audit all uses of the kmod command.
Medium Severity
Without generating audit records specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). When a user logs on, the auid is set to the uid of the account being authenticated. Daemons are not user sessions and have the loginuid set to -1. The auid representation is an unsigned 32-bit integer, which equals 4294967295. The audit system interprets -1, 4294967295, and "unset" in the same way. The system call rules are loaded into a matching engine that intercepts each system call made by all programs on the system. Therefore, it is very important to use system call rules only when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. The performance can be helped, however, by combining system calls into one rule whenever possible. Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215, SRG-OS-000471-GPOS-00216, SRG-OS-000477-GPOS-00222
SRG-OS-000037-GPOS-00015
1 Rule
AlmaLinux OS 9 must generate audit records for any use of the "newgrp" command.
Medium Severity
Without generating audit records specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). When a user logs on, the auid is set to the uid of the account being authenticated. Daemons are not user sessions and have the loginuid set to -1. The auid representation is an unsigned 32-bit integer, which equals 4294967295. The audit system interprets -1, 4294967295, and "unset" in the same way. The system call rules are loaded into a matching engine that intercepts each system call made by all programs on the system. Therefore, it is very important to use system call rules only when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. The performance can be helped, however, by combining system calls into one rule whenever possible. Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215
SRG-OS-000037-GPOS-00015
1 Rule
AlmaLinux OS 9 must generate audit records for any use of the "passwd" command.
Medium Severity
Without generating audit records specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). When a user logs on, the auid is set to the uid of the account being authenticated. Daemons are not user sessions and have the loginuid set to -1. The auid representation is an unsigned 32-bit integer, which equals 4294967295. The audit system interprets -1, 4294967295, and "unset" in the same way. The system call rules are loaded into a matching engine that intercepts each system call made by all programs on the system. Therefore, it is very important to use system call rules only when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. The performance can be helped, however, by combining system calls into one rule whenever possible. Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215
SRG-OS-000037-GPOS-00015
1 Rule
AlmaLinux OS 9 must generate audit records for any use of the "postdrop" command.
Medium Severity
Without generating audit records specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). When a user logs on, the auid is set to the uid of the account being authenticated. Daemons are not user sessions and have the loginuid set to -1. The auid representation is an unsigned 32-bit integer, which equals 4294967295. The audit system interprets -1, 4294967295, and "unset" in the same way. The system call rules are loaded into a matching engine that intercepts each system call made by all programs on the system. Therefore, it is very important to use system call rules only when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. The performance can be helped, however, by combining system calls into one rule whenever possible. Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215
SRG-OS-000037-GPOS-00015
1 Rule
AlmaLinux OS 9 must generate audit records for any use of the "postqueue" command.
Medium Severity
Without generating audit records specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). When a user logs on, the auid is set to the uid of the account being authenticated. Daemons are not user sessions and have the loginuid set to -1. The auid representation is an unsigned 32-bit integer, which equals 4294967295. The audit system interprets -1, 4294967295, and "unset" in the same way. The system call rules are loaded into a matching engine that intercepts each system call made by all programs on the system. Therefore, it is very important to use system call rules only when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. The performance can be helped, however, by combining system calls into one rule whenever possible. Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215
SRG-OS-000037-GPOS-00015
1 Rule
AlmaLinux OS 9 must generate audit records for any use of the "su" command.
Medium Severity
Without generating audit record specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). When a user logs on, the auid is set to the uid of the account being authenticated. Daemons are not user sessions and have the loginuid set to -1. The auid representation is an unsigned 32-bit integer, which equals 4294967295. The audit system interprets -1, 4294967295, and "unset" in the same way. The system call rules are loaded into a matching engine that intercepts each system call made by all programs on the system. Therefore, it is very important to use system call rules only when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. The performance can be helped, however, by combining system calls into one rule whenever possible. Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000064-GPOS-00033, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215, SRG-OS-000466-GPOS-00210
SRG-OS-000037-GPOS-00015
1 Rule
AlmaLinux OS 9 must generate audit records for any use of the "sudo" command.
Medium Severity
Without generating audit record specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). When a user logs on, the auid is set to the uid of the account being authenticated. Daemons are not user sessions and have the loginuid set to -1. The auid representation is an unsigned 32-bit integer, which equals 4294967295. The audit system interprets -1, 4294967295, and "unset" in the same way. The system call rules are loaded into a matching engine that intercepts each system call made by all programs on the system. Therefore, it is very important to use system call rules only when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. The performance can be helped, however, by combining system calls into one rule whenever possible. Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000064-GPOS-00033, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215, SRG-OS-000466-GPOS-00210
SRG-OS-000037-GPOS-00015
1 Rule
AlmaLinux OS 9 must generate audit records for any use of the "semanage" command.
Medium Severity
Without generating audit records specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). When a user logs on, the auid is set to the uid of the account being authenticated. Daemons are not user sessions and have the loginuid set to -1. The auid representation is an unsigned 32-bit integer, which equals 4294967295. The audit system interprets -1, 4294967295, and "unset" in the same way. The system call rules are loaded into a matching engine that intercepts each system call made by all programs on the system. Therefore, it is very important to use system call rules only when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. The performance can be helped, however, by combining system calls into one rule whenever possible. Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215, SRG-OS-000463-GPOS-00207, SRG-OS-000465-GPOS-00209
SRG-OS-000037-GPOS-00015
1 Rule
AlmaLinux OS 9 must generate audit records for any use of the "setfacl" command.
Medium Severity
Without generating audit records specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). When a user logs on, the auid is set to the uid of the account being authenticated. Daemons are not user sessions and have the loginuid set to -1. The auid representation is an unsigned 32-bit integer, which equals 4294967295. The audit system interprets -1, 4294967295, and "unset" in the same way. The system call rules are loaded into a matching engine that intercepts each system call made by all programs on the system. Therefore, it is very important to use system call rules only when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. The performance can be helped, however, by combining system calls into one rule whenever possible. Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215
SRG-OS-000037-GPOS-00015
1 Rule
AlmaLinux OS 9 must generate audit records for any use of the "setfiles" command.
Medium Severity
Without generating audit records specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). When a user logs on, the auid is set to the uid of the account being authenticated. Daemons are not user sessions and have the loginuid set to -1. The auid representation is an unsigned 32-bit integer, which equals 4294967295. The audit system interprets -1, 4294967295, and "unset" in the same way. The system call rules are loaded into a matching engine that intercepts each system call made by all programs on the system. Therefore, it is very important to use system call rules only when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. The performance can be helped, however, by combining system calls into one rule whenever possible. Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215, SRG-OS-000463-GPOS-00207, SRG-OS-000465-GPOS-00209
SRG-OS-000037-GPOS-00015
1 Rule
AlmaLinux OS 9 must generate audit records for any use of the "setsebool" command.
Medium Severity
Without generating audit records specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). When a user logs on, the auid is set to the uid of the account being authenticated. Daemons are not user sessions and have the loginuid set to -1. The auid representation is an unsigned 32-bit integer, which equals 4294967295. The audit system interprets -1, 4294967295, and "unset" in the same way. The system call rules are loaded into a matching engine that intercepts each system call made by all programs on the system. Therefore, it is very important to use system call rules only when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. The performance can be helped, however, by combining system calls into one rule whenever possible. Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215, SRG-OS-000463-GPOS-00207, SRG-OS-000465-GPOS-00209
SRG-OS-000037-GPOS-00015
1 Rule
AlmaLinux OS 9 must generate audit records for any use of the "ssh-agent" command.
Medium Severity
Without generating audit records specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). When a user logs on, the auid is set to the uid of the account being authenticated. Daemons are not user sessions and have the loginuid set to -1. The auid representation is an unsigned 32-bit integer, which equals 4294967295. The audit system interprets -1, 4294967295, and "unset" in the same way. The system call rules are loaded into a matching engine that intercepts each system call made by all programs on the system. Therefore, it is very important to use system call rules only when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. The performance can be helped, however, by combining system calls into one rule whenever possible. Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215
SRG-OS-000037-GPOS-00015
1 Rule
AlmaLinux OS 9 must generate audit records for any use of the "ssh-keysign" command.
Medium Severity
Without generating audit records specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). When a user logs on, the auid is set to the uid of the account being authenticated. Daemons are not user sessions and have the loginuid set to -1. The auid representation is an unsigned 32-bit integer, which equals 4294967295. The audit system interprets -1, 4294967295, and "unset" in the same way. The system call rules are loaded into a matching engine that intercepts each system call made by all programs on the system. Therefore, it is very important to use system call rules only when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. The performance can be helped, however, by combining system calls into one rule whenever possible. Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215
SRG-OS-000037-GPOS-00015
1 Rule
AlmaLinux OS 9 must generate audit records for any use of the "sudoedit" command.
Medium Severity
Without generating audit records specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). When a user logs on, the auid is set to the uid of the account being authenticated. Daemons are not user sessions and have the loginuid set to -1. The auid representation is an unsigned 32-bit integer, which equals 4294967295. The audit system interprets -1, 4294967295, and "unset" in the same way. The system call rules are loaded into a matching engine that intercepts each system call made by all programs on the system. Therefore, it is very important to use system call rules only when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. The performance can be helped, however, by combining system calls into one rule whenever possible. Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215
SRG-OS-000037-GPOS-00015
1 Rule
AlmaLinux OS 9 must generate audit records for any use of the "pam_timestamp_check" command.
Medium Severity
Without generating audit records specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). When a user logs on, the auid is set to the uid of the account being authenticated. Daemons are not user sessions and have the loginuid set to -1. The auid representation is an unsigned 32-bit integer, which equals 4294967295. The audit system interprets -1, 4294967295, and "unset" in the same way. The system call rules are loaded into a matching engine that intercepts each system call made by all programs on the system. Therefore, it is very important to use system call rules only when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. The performance can be helped, however, by combining system calls into one rule whenever possible. Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215
SRG-OS-000037-GPOS-00015
1 Rule
AlmaLinux OS 9 must generate audit records for any use of the "unix_chkpwd" command.
Medium Severity
Without generating audit records specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). When a user logs on, the auid is set to the uid of the account being authenticated. Daemons are not user sessions and have the loginuid set to -1. The auid representation is an unsigned 32-bit integer, which equals 4294967295. The audit system interprets -1, 4294967295, and "unset" in the same way. The system call rules are loaded into a matching engine that intercepts each system call made by all programs on the system. Therefore, it is very important to use system call rules only when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. The performance can be helped, however, by combining system calls into one rule whenever possible. Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215
SRG-OS-000037-GPOS-00015
1 Rule
AlmaLinux OS 9 must generate audit records for any use of the "unix_update" command.
Medium Severity
Without generating audit records specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). When a user logs on, the auid is set to the uid of the account being authenticated. Daemons are not user sessions and have the loginuid set to -1. The auid representation is an unsigned 32-bit integer, which equals 4294967295. The audit system interprets -1, 4294967295, and "unset" in the same way. The system call rules are loaded into a matching engine that intercepts each system call made by all programs on the system. Therefore, it is very important to use system call rules only when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. The performance can be helped, however, by combining system calls into one rule whenever possible. Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000064-GPOS-00033, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215
SRG-OS-000037-GPOS-00015
1 Rule
AlmaLinux OS 9 must generate audit records for any use of the "userhelper" command.
Medium Severity
Without generating audit records specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). When a user logs on, the auid is set to the uid of the account being authenticated. Daemons are not user sessions and have the loginuid set to -1. The auid representation is an unsigned 32-bit integer, which equals 4294967295. The audit system interprets -1, 4294967295, and "unset" in the same way. The system call rules are loaded into a matching engine that intercepts each system call made by all programs on the system. Therefore, it is very important to use system call rules only when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. The performance can be helped, however, by combining system calls into one rule whenever possible. Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215
SRG-OS-000037-GPOS-00015
1 Rule
AlmaLinux OS 9 must generate audit records for any use of the "usermod" command.
Medium Severity
Without generating audit records specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). When a user logs on, the auid is set to the uid of the account being authenticated. Daemons are not user sessions and have the loginuid set to -1. The auid representation is an unsigned 32-bit integer, which equals 4294967295. The audit system interprets -1, 4294967295, and "unset" in the same way. The system call rules are loaded into a matching engine that intercepts each system call made by all programs on the system. Therefore, it is very important to use system call rules only when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. The performance can be helped, however, by combining system calls into one rule whenever possible. Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215, SRG-OS-000466-GPOS-00210
SRG-OS-000037-GPOS-00015
1 Rule
AlmaLinux OS 9 must audit all uses of the setxattr, fsetxattr, lsetxattr, removexattr, fremovexattr, and lremovexattr system calls.
Medium Severity
Without generating audit records specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). When a user logs on, the auid is set to the uid of the account being authenticated. Daemons are not user sessions and have the loginuid set to -1. The auid representation is an unsigned 32-bit integer, which equals 4294967295. The audit system interprets -1, 4294967295, and "unset" in the same way. The system call rules are loaded into a matching engine that intercepts each system call made by all programs on the system. Therefore, it is very important to use system call rules only when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. The performance can be helped, however, by combining system calls into one rule whenever possible. Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000458-GPOS-00203, SRG-OS-000462-GPOS-00206, SRG-OS-000463-GPOS-00207, SRG-OS-000471-GPOS-00215, SRG-OS-000474-GPOS-00219, SRG-OS-000466-GPOS-00210, SRG-OS-000064-GPOS-00033
SRG-OS-000341-GPOS-00132
1 Rule
AlmaLinux OS 9 must allocate an audit_backlog_limit of sufficient size to capture processes that start prior to the audit daemon.
Low Severity
Without the capability to generate audit records, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. If auditing is enabled late in the startup process, the actions of some startup processes may not be audited. Some audit systems also maintain state information only available if auditing is enabled before a given process is created. Audit records can be generated from various components within the information system (e.g., module or policy filter). Allocating an audit_backlog_limit of sufficient size is critical in maintaining a stable boot process. With an insufficient limit allocated, the system is susceptible to boot failures and crashes.
SRG-OS-000341-GPOS-00132
1 Rule
AlmaLinux OS 9 must use a separate file system for the system audit data path.
Low Severity
Placing "/var/log/audit" in its own partition enables better separation between audit files and other system files, and helps ensure that auditing cannot be halted due to the partition running out of space.
SRG-OS-000341-GPOS-00132
1 Rule
AlmaLinux OS 9 must allocate audit record storage capacity to store at least one week's worth of audit records.
Medium Severity
To ensure AlmaLinux OS 9 systems have a sufficient storage capacity in which to write the audit logs, AlmaLinux OS 9 needs to be able to allocate audit record storage capacity. The task of allocating audit record storage capacity is usually performed during initial installation of AlmaLinux OS 9.
SRG-OS-000479-GPOS-00224
1 Rule
AlmaLinux OS 9 audispd-plugins package must be installed.
Medium Severity
"audispd-plugins" provides plugins for the real-time interface to the audit subsystem, "audispd". These plugins can do things like relay events to remote machines or analyze events for suspicious behavior.
SRG-OS-000479-GPOS-00224
1 Rule
AlmaLinux OS 9 must label all offloaded audit logs before sending them to the central log server.
Medium Severity
When audit logs are not labelled before they are sent to a central log server, the audit data will not be able to be analyzed and tied back to the correct system.
SRG-OS-000479-GPOS-00224
1 Rule
AlmaLinux OS 9 must take appropriate action when the internal event queue is full.
Medium Severity
The audit system should have an action setup in the event the internal event queue becomes full so that no data is lost.
SRG-OS-000479-GPOS-00224
1 Rule
AlmaLinux OS 9 must be configured to offload audit records onto a different system from the system being audited via syslog.
Medium Severity
The auditd service does not include the ability to send audit records to a centralized server for management directly. However, it can use a plug-in for audit event multiplexor (audispd) to pass audit records to the local syslog server.
SRG-OS-000479-GPOS-00224
1 Rule
AlmaLinux OS 9 must authenticate the remote logging server for offloading audit logs via rsyslog.
Medium Severity
Information stored in one location is vulnerable to accidental or incidental deletion or alteration. Off-loading is a common process in information systems with limited audit storage capacity.
SRG-OS-000479-GPOS-00224
1 Rule
AlmaLinux OS 9 must encrypt the transfer of audit records offloaded onto a different system or media from the system being audited via rsyslog.
Medium Severity
Information stored in one location is vulnerable to accidental or incidental deletion or alteration. Off-loading is a common process in information systems with limited audit storage capacity.
SRG-OS-000479-GPOS-00224
1 Rule
AlmaLinux OS 9 must encrypt, via the gtls driver, the transfer of audit records offloaded onto a different system or media from the system being audited via rsyslog.
Medium Severity
Information stored in one location is vulnerable to accidental or incidental deletion or alteration. Off-loading is a common process in information systems with limited audit storage capacity.
SRG-OS-000342-GPOS-00133
1 Rule
AlmaLinux OS 9 must have the rsyslog package installed.
Medium Severity
rsyslogd is a system utility providing support for message logging. Support for both internet and Unix domain sockets enables this utility to support both local and remote logging. Couple this utility with "gnutls" (which is a secure communications library implementing the SSL, TLS, and DTLS protocols), to create a method to securely encrypt and offload auditing.
SRG-OS-000342-GPOS-00133
1 Rule
AlmaLinux OS 9 must be configured to forward audit records via TCP to a different system or media from the system being audited via rsyslog.
Low Severity
Information stored in one location is vulnerable to accidental or incidental deletion or alteration. Off-loading is a common process in information systems with limited audit storage capacity.
SRG-OS-000342-GPOS-00133
1 Rule
The rsyslog service on AlmaLinux OS 9 must be active.
Medium Severity
The "rsyslog" service must be running to provide logging services, which are essential to system administration.
SRG-OS-000343-GPOS-00134
1 Rule
AlmaLinux OS 9 must take action when allocated audit record storage volume reaches 95 percent of the audit record storage capacity.
Medium Severity
If security personnel are not notified immediately when storage volume reaches 75 percent usage, they are unable to plan for audit record storage capacity expansion.
SRG-OS-000343-GPOS-00134
1 Rule
AlmaLinux OS 9 must take action when allocated audit record storage volume reaches 95 percent of the repository maximum audit record storage capacity.
Medium Severity
If security personnel are not notified immediately when storage volume reaches 75 percent usage, they are unable to plan for audit record storage capacity expansion.
SRG-OS-000343-GPOS-00134
1 Rule
AlmaLinux OS 9 must take action when allocated audit record storage volume reaches 75 percent of the repository maximum audit record storage capacity.
Medium Severity
If security personnel are not notified immediately when storage volume reaches 75 percent usage, they are unable to plan for audit record storage capacity expansion.
SRG-OS-000343-GPOS-00134
1 Rule
AlmaLinux OS 9 must notify the system administrator (SA) and information system security officer (ISSO) (at a minimum) when allocated audit record storage volume reaches 75 percent usage.
Medium Severity
If security personnel are not notified immediately when storage volume reaches 75 percent usage, they are unable to plan for audit record storage capacity expansion.
SRG-OS-000046-GPOS-00022
1 Rule
AlmaLinux OS 9 System Administrator (SA) and/or information system security officer (ISSO) (at a minimum) must be alerted of an audit processing failure event.
Medium Severity
It is critical for the appropriate personnel to be aware if a system is at risk of failing to process audit logs as required. Without this notification, the security personnel may be unaware of an impending failure of the audit capability, and system operation may be adversely affected. Audit processing failures include software/hardware errors, failures in the audit capturing mechanisms, and audit storage capacity being reached or exceeded. This requirement applies to each audit data storage repository (i.e., distinct information system component where audit records are stored), the centralized audit storage capacity of organizations (i.e., all audit data storage repositories combined), or both.
SRG-OS-000046-GPOS-00022
1 Rule
AlmaLinux OS 9 must have mail aliases to notify the information system security officer (ISSO) and system administrator (SA) (at a minimum) in the event of an audit processing failure.
Medium Severity
It is critical for the appropriate personnel to be aware if a system is at risk of failing to process audit logs as required. Without this notification, the security personnel may be unaware of an impending failure of the audit capability, and system operation may be adversely affected. Audit processing failures include software/hardware errors, failures in the audit capturing mechanisms, and audit storage capacity being reached or exceeded. This requirement applies to each audit data storage repository (i.e., distinct information system component where audit records are stored), the centralized audit storage capacity of organizations (i.e., all audit data storage repositories combined), or both.
SRG-OS-000047-GPOS-00023
1 Rule
AlmaLinux OS 9 audit system must take appropriate action when an error writing to the audit storage volume occurs.
Medium Severity
It is critical that when the operating system is at risk of failing to process audit logs as required, it takes action to mitigate the failure. Audit processing failures include software/hardware errors; failures in the audit capturing mechanisms; and audit storage capacity being reached or exceeded. Responses to audit failure depend upon the nature of the failure mode. When availability is an overriding concern, other approved actions in response to an audit failure are as follows: 1) If the failure was caused by the lack of audit record storage capacity, the operating system must continue generating audit records if possible (automatically restarting the audit service if necessary), overwriting the oldest audit records in a first-in-first-out manner. 2) If audit records are sent to a centralized collection server and communication with this server is lost or the server fails, the operating system must queue audit records locally until communication is restored or until the audit records are retrieved manually. Upon restoration of the connection to the centralized collection server, action should be taken to synchronize the local audit data with the collection server.
SRG-OS-000047-GPOS-00023
1 Rule
AlmaLinux OS 9 audit system must take appropriate action when the audit storage volume is full.
Medium Severity
It is critical that when the operating system is at risk of failing to process audit logs as required, it takes action to mitigate the failure. Audit processing failures include software/hardware errors; failures in the audit capturing mechanisms; and audit storage capacity being reached or exceeded. Responses to audit failure depend upon the nature of the failure mode. When availability is an overriding concern, other approved actions in response to an audit failure are as follows: 1) If the failure was caused by the lack of audit record storage capacity, the operating system must continue generating audit records if possible (automatically restarting the audit service if necessary), overwriting the oldest audit records in a first-in-first-out manner. 2) If audit records are sent to a centralized collection server and communication with this server is lost or the server fails, the operating system must queue audit records locally until communication is restored or until the audit records are retrieved manually. Upon restoration of the connection to the centralized collection server, action should be taken to synchronize the local audit data with the collection server.
SRG-OS-000047-GPOS-00023
1 Rule
AlmaLinux OS 9 must take appropriate action when a critical audit processing failure occurs.
Medium Severity
It is critical that when the operating system is at risk of failing to process audit logs as required, it takes action to mitigate the failure. Audit processing failures include software/hardware errors; failures in the audit capturing mechanisms; and audit storage capacity being reached or exceeded. Responses to audit failure depend upon the nature of the failure mode. When availability is an overriding concern, other approved actions in response to an audit failure are as follows: 1) If the failure was caused by the lack of audit record storage capacity, the operating system must continue generating audit records if possible (automatically restarting the audit service if necessary), overwriting the oldest audit records in a first-in-first-out manner. 2) If audit records are sent to a centralized collection server and communication with this server is lost or the server fails, the operating system must queue audit records locally until communication is restored or until the audit records are retrieved manually. Upon restoration of the connection to the centralized collection server, action should be taken to synchronize the local audit data with the collection server.
SRG-OS-000047-GPOS-00023
1 Rule
AlmaLinux OS 9 audit system must make full use of the audit storage space.
Medium Severity
max_log_file (size in megabytes) multiplied by num_logs must make full use of the auditd storage volume (separate to the root partition). If max_log_file_action is set to ROTATE or KEEP_LOGS then max_log_file must be set to a value that makes the most use of the storage available.
SRG-OS-000047-GPOS-00023
1 Rule
AlmaLinux OS 9 audit system must take appropriate action when the audit files have reached maximum size.
Medium Severity
It is critical that when the operating system is at risk of failing to process audit logs as required, it takes action to mitigate the failure. Audit processing failures include software/hardware errors; failures in the audit capturing mechanisms; and audit storage capacity being reached or exceeded. Responses to audit failure depend upon the nature of the failure mode. When availability is an overriding concern, other approved actions in response to an audit failure are as follows: 1) If the failure was caused by the lack of audit record storage capacity, the operating system must continue generating audit records if possible (automatically restarting the audit service if necessary), overwriting the oldest audit records in a first-in-first-out manner. 2) If audit records are sent to a centralized collection server and communication with this server is lost or the server fails, the operating system must queue audit records locally until communication is restored or until the audit records are retrieved manually. Upon restoration of the connection to the centralized collection server, action should be taken to synchronize the local audit data with the collection server.
SRG-OS-000047-GPOS-00023
1 Rule
AlmaLinux OS 9 audit system must retain an optimal number of audit records.
Medium Severity
max_log_file (size in megabytes) multiplied by num_logs must make full use of the auditd storage volume (separate to the root partition). If max_log_file_action is set to ROTATE or KEEP_LOGS then num_logs must be set to a value between 2 and 99.
SRG-OS-000051-GPOS-00024
1 Rule
AlmaLinux OS 9 must periodically flush audit records to disk to prevent the loss of audit records.
Medium Severity
If option "freq" is not set to a value that requires audit records being written to disk after a threshold number is reached, then audit records may be lost.
SRG-OS-000042-GPOS-00021
1 Rule
The auditd service must be enabled on AlmaLinux OS 9.
Medium Severity
Without establishing what type of events occurred, the source of events, where events occurred, and the outcome of events, it would be difficult to establish, correlate, and investigate the events leading up to an outage or attack. Audit record content that may be necessary to satisfy this requirement includes, for example, time stamps, source and destination addresses, user/process identifiers, event descriptions, success/fail indications, filenames involved, and access control or flow control rules invoked. Associating event types with detected events in audit logs provides a means of investigating an attack, recognizing resource usage or capacity thresholds, or identifying an improperly configured AlmaLinux OS 9 system. Satisfies: SRG-OS-000042-GPOS-00021, SRG-OS-000051-GPOS-00024, SRG-OS-000392-GPOS-00172, SRG-OS-000122-GPOS-00063, SRG-OS-000473-GPOS-00218, SRG-OS-000472-GPOS-00217, SRG-OS-000474-GPOS-00219, SRG-OS-000365-GPOS-00152, SRG-OS-000358-GPOS-00145, SRG-OS-000348-GPOS-00136, SRG-OS-000349-GPOS-00137, SRG-OS-000350-GPOS-00138, SRG-OS-000351-GPOS-00139, SRG-OS-000352-GPOS-00140, SRG-OS-000353-GPOS-00141, SRG-OS-000354-GPOS-00142, SRG-OS-000337-GPOS-00129, SRG-OS-000062-GPOS-00031, SRG-OS-000054-GPOS-00025
SRG-OS-000355-GPOS-00143
1 Rule
The chronyd service must be enabled.
Medium Severity
Inaccurate time stamps make it more difficult to correlate events and can lead to an inaccurate analysis. Determining the correct time a particular event occurred on a system is critical when conducting forensic analysis and investigating system events. Sources outside the configured acceptable allowance (drift) may be inaccurate. Synchronizing internal information system clocks provides uniformity of time stamps for information systems with multiple system clocks and systems connected over a network. Organizations should consider endpoints that may not have regular access to the authoritative time server (e.g., mobile, teleworking, and tactical endpoints). Satisfies: SRG-OS-000355-GPOS-00143, SRG-OS-000359-GPOS-00146
SRG-OS-000355-GPOS-00143
1 Rule
AlmaLinux OS 9 must have the chrony package installed.
Medium Severity
Inaccurate time stamps make it more difficult to correlate events and can lead to an inaccurate analysis. Determining the correct time a particular event occurred on a system is critical when conducting forensic analysis and investigating system events. Sources outside the configured acceptable allowance (drift) may be inaccurate. Synchronizing internal information system clocks provides uniformity of time stamps for information systems with multiple system clocks and systems connected over a network. Organizations should consider endpoints that may not have regular access to the authoritative time server (e.g., mobile, teleworking, and tactical endpoints). Satisfies: SRG-OS-000355-GPOS-00143, SRG-OS-000359-GPOS-00146
SRG-OS-000356-GPOS-00144
1 Rule
AlmaLinux OS 9 must securely compare internal information system clocks at least every 24 hours.
Medium Severity
Inaccurate time stamps make it more difficult to correlate events and can lead to an inaccurate analysis. Determining the correct time a particular event occurred on a system is critical when conducting forensic analysis and investigating system events. Synchronizing internal information system clocks provides uniformity of time stamps for information systems with multiple system clocks and systems connected over a network. Organizations should consider setting time periods for different types of systems (e.g., financial, legal, or mission-critical systems). Organizations should also consider endpoints that may not have regular access to the authoritative time server (e.g., mobile, teleworking, and tactical endpoints). This requirement is related to the comparison done every 24 hours in SRG-OS-000355 because a comparison must be done to determine the time difference. Satisfies: SRG-OS-000356-GPOS-00144, SRG-OS-000359-GPOS-00146, SRG-OS-000785-GPOS-00250
SRG-OS-000057-GPOS-00027
1 Rule
AlmaLinux OS 9 audit log directory must be owned by root to prevent unauthorized read access.
Medium Severity
Unauthorized disclosure of audit records can reveal system and configuration data to attackers, thus compromising its confidentiality. Audit information includes all information (e.g., audit records, audit settings, audit reports) needed to successfully audit operating system activity. Satisfies: SRG-OS-000057-GPOS-00027, SRG-OS-000059-GPOS-00029
SRG-OS-000057-GPOS-00027
1 Rule
AlmaLinux OS 9 audit log directory must have 0700 permissions to prevent unauthorized read access.
Medium Severity
Unauthorized disclosure of audit records can reveal system and configuration data to attackers, thus compromising its confidentiality. Audit information includes all information (e.g., audit records, audit settings, audit reports) needed to successfully audit operating system activity. Satisfies: SRG-OS-000057-GPOS-00027, SRG-OS-000059-GPOS-00029
SRG-OS-000057-GPOS-00027
1 Rule
AlmaLinux OS 9 audit logs must be owned by the root group to prevent unauthorized read access.
Medium Severity
Unauthorized disclosure of audit records can reveal system and configuration data to attackers, thus compromising its confidentiality. Audit information includes all information (e.g., audit records, audit settings, audit reports) needed to successfully audit operating system activity. Satisfies: SRG-OS-000057-GPOS-00027, SRG-OS-000059-GPOS-00029
SRG-OS-000057-GPOS-00027
1 Rule
AlmaLinux OS 9 audit logs must be owned by root to prevent unauthorized read access.
Medium Severity
Unauthorized disclosure of audit records can reveal system and configuration data to attackers, thus compromising its confidentiality. Audit information includes all information (e.g., audit records, audit settings, audit reports) needed to successfully audit operating system activity. Satisfies: SRG-OS-000057-GPOS-00027, SRG-OS-000059-GPOS-00029
SRG-OS-000057-GPOS-00027
1 Rule
AlmaLinux OS 9 audit logs must have 0600 permissions to prevent unauthorized read access.
Medium Severity
Unauthorized disclosure of audit records can reveal system and configuration data to attackers, thus compromising its confidentiality. Audit information includes all information (e.g., audit records, audit settings, audit reports) needed to successfully audit operating system activity. Satisfies: SRG-OS-000057-GPOS-00027, SRG-OS-000059-GPOS-00029
SRG-OS-000256-GPOS-00097
1 Rule
AlmaLinux OS 9 audit tools must be group-owned by root.
Medium Severity
Protecting audit information also includes identifying and protecting the tools used to view and manipulate log data. Therefore, protecting audit tools is necessary to prevent unauthorized operation on audit information. AlmaLinux OS 9 systems providing tools to interface with audit information will leverage user permissions and roles identifying the user accessing the tools, and the corresponding rights the user enjoys, to make access decisions regarding the access to audit tools. Audit tools include, but are not limited to, vendor-provided and open source audit tools needed to successfully view and manipulate audit information system activity and records. Audit tools include custom queries and report generators.
SRG-OS-000256-GPOS-00097
1 Rule
AlmaLinux OS 9 audit tools must be owned by root.
Medium Severity
Protecting audit information also includes identifying and protecting the tools used to view and manipulate log data. Therefore, protecting audit tools is necessary to prevent unauthorized operation on audit information. AlmaLinux OS 9 systems providing tools to interface with audit information will leverage user permissions and roles identifying the user accessing the tools, and the corresponding rights the user enjoys, to make access decisions regarding the access to audit tools. Audit tools include, but are not limited to, vendor-provided and open source audit tools needed to successfully view and manipulate audit information system activity and records. Audit tools include custom queries and report generators. Satisfies: SRG-OS-000256-GPOS-00097, SRG-OS-000258-GPOS-00099
SRG-OS-000256-GPOS-00097
1 Rule
AlmaLinux OS 9 audit tools must have a mode of 0755 or less permissive.
Medium Severity
Protecting audit information also includes identifying and protecting the tools used to view and manipulate log data. Therefore, protecting audit tools is necessary to prevent unauthorized operation on audit information. AlmaLinux OS 9 systems providing tools to interface with audit information will leverage user permissions and roles identifying the user accessing the tools, and the corresponding rights the user enjoys, to make access decisions regarding the access to audit tools. Audit tools include, but are not limited to, vendor-provided and open source audit tools needed to successfully view and manipulate audit information system activity and records. Audit tools include custom queries and report generators. Satisfies: SRG-OS-000256-GPOS-00097, SRG-OS-000258-GPOS-00099
SRG-OS-000058-GPOS-00028
1 Rule
AlmaLinux OS 9 audit system must protect logon UIDs from unauthorized change.
Medium Severity
If modification of login user identifiers (UIDs) is not prevented, they can be changed by nonprivileged users and make auditing complicated or impossible.
SRG-OS-000278-GPOS-00108
1 Rule
AlmaLinux OS 9 must use cryptographic mechanisms to protect the integrity of audit tools.
Medium Severity
Protecting the integrity of the tools used for auditing purposes is a critical step toward ensuring the integrity of audit information. Audit information includes all information (e.g., audit records, audit settings, and audit reports) needed to successfully audit information system activity. Satisfies: SRG-OS-000278-GPOS-00108, SRG-OS-000257-GPOS-00098
SRG-OS-000058-GPOS-00028
1 Rule
AlmaLinux OS 9 audit system must protect auditing rules from unauthorized change.
Medium Severity
Unauthorized disclosure of audit records can reveal system and configuration data to attackers, thus compromising its confidentiality. Audit information includes all information (e.g., audit records, audit settings, audit reports) needed to successfully audit AlmaLinux OS 9 system activity. In immutable mode, unauthorized users cannot execute changes to the audit system to potentially hide malicious activity and then put the audit rules back. A system reboot would be noticeable, and a system administrator could then investigate the unauthorized changes.