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XCCDF
Oracle Linux 7 Security Technical Implementation Guide
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243 rules organized in 243 groups
SRG-OS-000480-GPOS-00227
1 Rule
The Oracle Linux operating system must be configured so that the cryptographic hash of system files and commands matches vendor values.
High Severity
Without cryptographic integrity protections, system command and files 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 key used to generate the hash.
SRG-OS-000023-GPOS-00006
1 Rule
The Oracle Linux operating system 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
The 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." Satisfies: SRG-OS-000023-GPOS-00006, SRG-OS-000024-GPOS-00007, SRG-OS-000228-GPOS-00088
SRG-OS-000023-GPOS-00006
1 Rule
The Oracle Linux operating system must display the approved 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. "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." Satisfies: SRG-OS-000023-GPOS-00006, SRG-OS-000024-GPOS-00007, SRG-OS-000228-GPOS-00088
SRG-OS-000023-GPOS-00006
1 Rule
The Oracle Linux operating system 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." Satisfies: SRG-OS-000023-GPOS-00006, SRG-OS-000024-GPOS-00007
SRG-OS-000028-GPOS-00009
1 Rule
The Oracle Linux operating system must enable a user session lock until that user re-establishes access using established identification and authentication procedures.
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 reauthenticates. No other activity aside from reauthentication must unlock the system. Satisfies: SRG-OS-000028-GPOS-00009, SRG-OS-000030-GPOS-00011
SRG-OS-000375-GPOS-00160
1 Rule
The Oracle Linux operating system must uniquely identify and must authenticate users using multifactor authentication via a graphical user logon.
Medium Severity
To assure accountability and prevent unauthenticated access, users must be identified and authenticated to prevent potential misuse and compromise of the system. 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. Satisfies: SRG-OS-000375-GPOS-00161, SRG-OS-000377-GPOS-00162
SRG-OS-000029-GPOS-00010
1 Rule
The Oracle Linux operating system must prevent a user from overriding the screensaver lock-enabled 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 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. The ability to enable/disable a session lock is given to the user by default. Disabling the user’s ability to disengage the graphical user interface session lock ensures all sessions will lock after the specified period of time.
SRG-OS-000029-GPOS-00010
1 Rule
The Oracle Linux operating system must initiate a screensaver after a 15-minute period of inactivity for graphical user interfaces.
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 log out because of the temporary nature of the absence. Rather than relying on the user to lock the operating system session manually prior to leaving the workstation, operating systems must be able to identify when a user's session has idled, and take action to initiate the session lock. The session lock is implemented at the point where session activity can be determined and/or controlled.
SRG-OS-000029-GPOS-00010
1 Rule
The Oracle Linux operating system must prevent a user from overriding the screensaver 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 log out because of the temporary nature of the absence. Rather than relying on the user to lock the operating system session manually prior to leaving the workstation, operating systems must be able to identify when a user's session has idled, and take action to initiate the session lock. The session lock is implemented at the point where session activity can be determined and/or controlled.
SRG-OS-000029-GPOS-00010
1 Rule
The Oracle Linux operating system must prevent a user from overriding the session idle-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 log out because of the temporary nature of the absence. Rather than relying on the user to lock their operating system session manually prior to leaving the workstation, operating systems must be able to identify when a user's session has idled and take action to initiate the session lock. The session lock is implemented at the point where session activity can be determined and/or controlled.
SRG-OS-000029-GPOS-00010
1 Rule
The Oracle Linux operating system must initiate a session lock for the screensaver after a period of inactivity for graphical user interfaces.
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 log out 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, operating systems must be able to identify when a user's session has idled and take action to initiate the session lock. The session lock is implemented at the point where session activity can be determined and/or controlled.
SRG-OS-000029-GPOS-00010
1 Rule
The Oracle Linux operating system must prevent a user from overriding the screensaver idle-activation-enabled 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 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. The ability to enable/disable a session lock is given to the user by default. Disabling the user's ability to disengage the graphical user interface session lock provides the assurance that all sessions will lock after the specified period of time.
SRG-OS-000029-GPOS-00010
1 Rule
The Oracle Linux operating system must initiate a session lock for graphical user interfaces when the screensaver is activated.
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 log out because of the temporary nature of the absence. Rather than relying on the user to lock their operating system session manually prior to leaving the workstation, operating systems must be able to identify when a user's session has idled, and take action to initiate the session lock. The session lock is implemented at the point where session activity can be determined and/or controlled.
SRG-OS-000069-GPOS-00037
1 Rule
The Oracle Linux operating system must be configured so that /etc/pam.d/passwd implements /etc/pam.d/system-auth when changing passwords.
Medium Severity
Pluggable authentication modules (PAM) allow for a modular approach to integrating authentication methods. PAM operates in a top-down processing model and if the modules are not listed in the correct order, an important security function could be bypassed if stack entries are not centralized.
SRG-OS-000069-GPOS-00037
1 Rule
The Oracle Linux operating system must be configured so that when passwords are changed or new passwords are established, pwquality must 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. "pwquality" enforces complex password construction configuration and has the ability to limit brute-force attacks on the system. Satisfied: SRG-OS-000480-GPOS-00229, SRG-OS-000069-GPOS-00037
SRG-OS-000069-GPOS-00037
1 Rule
The Oracle Linux operating system must be configured so that when passwords are changed or new passwords are established, the new password must contain at least one upper-case character.
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 of several factors that determines how long it takes to crack a password. The more complex the password, the greater the number of possible combinations that must be tested before the password is compromised.
SRG-OS-000070-GPOS-00038
1 Rule
The Oracle Linux operating system must be configured so that when passwords are changed or new passwords are established, the new password must contain at least one lower-case character.
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 of several factors that determines how long it takes to crack a password. The more complex the password, the greater the number of possible combinations that must be tested before the password is compromised.
SRG-OS-000071-GPOS-00039
1 Rule
The Oracle Linux operating system must be configured so that when passwords are changed or new passwords are assigned, the new password must contain at least one numeric character.
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 of several factors that determines how long it takes to crack a password. The more complex the password, the greater the number of possible combinations that must be tested before the password is compromised.
SRG-OS-000266-GPOS-00101
1 Rule
The Oracle Linux operating system must be configured so that when passwords are changed or new passwords are established, the new password must contain at least one special character.
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
The Oracle Linux operating system must be configured so that when passwords are changed a minimum of eight of the total number of characters must be 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
The Oracle Linux operating system must be configured so that when passwords are changed a minimum of four character classes must be 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
The Oracle Linux operating system must be configured so that when passwords are changed the number of repeating consecutive characters must not be more than three characters.
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 of several factors 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
The Oracle Linux operating system must be configured so that when passwords are changed the number of repeating characters of the same character class must not be more than four characters.
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 of several factors 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
The Oracle Linux operating system must be configured so that the PAM system service is configured to store only encrypted representations of passwords.
Medium Severity
Passwords need to 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. Passwords encrypted with a weak algorithm are no more protected than if they are kept in plain text.
SRG-OS-000073-GPOS-00041
1 Rule
The Oracle Linux operating system must be configured to use the shadow file to store only encrypted representations of passwords.
Medium Severity
Passwords need to 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. Passwords encrypted with a weak algorithm are no more protected than if they are kept in plain text.
SRG-OS-000073-GPOS-00041
1 Rule
The Oracle Linux operating system must be configured so that user and group account administration utilities are configured to store only encrypted representations of passwords.
Medium Severity
Passwords need to 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. Passwords encrypted with a weak algorithm are no more protected than if they are kept in plain text.
SRG-OS-000075-GPOS-00043
1 Rule
The Oracle Linux operating system must be configured so that passwords for new users are restricted to a 24 hours/1 day minimum lifetime.
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, the password could be repeatedly changed in a short period of time to defeat the organization's policy regarding password reuse.
SRG-OS-000075-GPOS-00043
1 Rule
The Oracle Linux operating system must be configured so that passwords are restricted to a 24 hours/1 day minimum lifetime.
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, the password could be repeatedly changed in a short period of time to defeat the organization's policy regarding password reuse.
SRG-OS-000076-GPOS-00044
1 Rule
The Oracle Linux operating system must be configured so that passwords for new users are restricted to a 60-day maximum lifetime.
Medium Severity
Any password, no matter how complex, can eventually be cracked. Therefore, passwords need to 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
The Oracle Linux operating system must be configured so that existing passwords are restricted to a 60-day maximum lifetime.
Medium Severity
Any password, no matter how complex, can eventually be cracked. Therefore, passwords need to 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-000078-GPOS-00046
1 Rule
The Oracle Linux operating system must be configured so that passwords are a minimum of 15 characters in length.
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 increase exponentially the time and/or resources required to compromise the password.
SRG-OS-000480-GPOS-00227
1 Rule
The Oracle Linux operating system must not allow accounts configured with blank or null passwords.
High 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.
SRG-OS-000106-GPOS-00053
1 Rule
The Oracle Linux operating system must be configured so that the SSH daemon does not allow authentication using an empty password.
High Severity
Configuring this setting for the SSH daemon provides additional assurance that remote logon via SSH will require a password, even in the event of misconfiguration elsewhere.
SRG-OS-000118-GPOS-00060
1 Rule
The Oracle Linux operating system must disable account identifiers (individuals, groups, roles, and devices) if the password expires.
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. Owners of inactive accounts will not notice if unauthorized access to their user account has been obtained. Operating systems need to track periods of inactivity and disable application identifiers after 35 days of inactivity.
SRG-OS-000021-GPOS-00005
1 Rule
The Oracle Linux operating system must be configured to lock accounts for a minimum of 15 minutes after three unsuccessful logon attempts within a 15-minute timeframe.
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. Satisfies: SRG-OS-000329-GPOS-00128, SRG-OS-000021-GPOS-00005
SRG-OS-000329-GPOS-00128
1 Rule
The Oracle Linux operating system must lock the associated account after three unsuccessful root logon attempts are made within a 15-minute 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 forcing, is reduced. Limits are imposed by locking the account. Satisfies: SRG-OS-000329-GPOS-00128, SRG-OS-000021-GPOS-00005
SRG-OS-000373-GPOS-00156
1 Rule
The Oracle Linux operating system must be configured so that users must provide a password for privilege escalation.
Medium Severity
Without reauthentication, users may access resources or perform tasks for which authorization has not been granted. When operating systems provide the capability to escalate a functional capability, it is critical the user reauthenticate. Satisfies: SRG-OS-000373-GPOS-00156, SRG-OS-000373-GPOS-00157, SRG-OS-000373-GPOS-00158
SRG-OS-000480-GPOS-00226
1 Rule
The Oracle Linux operating system must be configured so that the delay between logon prompts following a failed console logon attempt is at least four seconds.
Medium Severity
Configuring the operating system to implement organization-wide security implementation guides and security checklists verifies compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example, registry settings; account, file, and directory permission settings; and settings for functions, ports, protocols, services, and remote connections.
SRG-OS-000480-GPOS-00229
1 Rule
The Oracle Linux operating system must not allow an unattended or automatic logon to the system via a graphical user interface.
High Severity
Failure to restrict system access to authenticated users negatively impacts operating system security.
SRG-OS-000480-GPOS-00229
1 Rule
The Oracle Linux operating system must not allow an unrestricted logon to the system.
High Severity
Failure to restrict system access to authenticated users negatively impacts operating system security.
SRG-OS-000480-GPOS-00229
1 Rule
The Oracle Linux operating system must not allow users to override SSH environment variables.
Medium Severity
Failure to restrict system access to authenticated users negatively impacts operating system security.
SRG-OS-000480-GPOS-00229
1 Rule
The Oracle Linux operating system must not allow a non-certificate trusted host SSH logon to the system.
Medium Severity
Failure to restrict system access to authenticated users negatively impacts operating system security.
SRG-OS-000080-GPOS-00048
1 Rule
The Oracle Linux operating system must require authentication upon booting into single-user and maintenance modes.
Medium Severity
If the system does not require valid root authentication before it boots into single-user or maintenance mode, anyone who invokes single-user or maintenance mode is granted privileged access to all files on the system.
SRG-OS-000080-GPOS-00048
1 Rule
Oracle Linux operating systems version 7.2 or newer with a Basic Input/Output System (BIOS) must require authentication upon booting into single-user and maintenance modes.
High Severity
If the system does not require valid authentication before it boots into single-user or maintenance mode, anyone who invokes single-user or maintenance mode is granted privileged access to all files on the system. GRUB 2 is the default boot loader for Oracle Linux 7 and is designed to require a password to boot into single-user mode or make modifications to the boot menu.
SRG-OS-000080-GPOS-00048
1 Rule
Oracle Linux operating systems version 7.2 or newer using Unified Extensible Firmware Interface (UEFI) must require authentication upon booting into single-user and maintenance modes.
High Severity
If the system does not require valid authentication before it boots into single-user or maintenance mode, anyone who invokes single-user or maintenance mode is granted privileged access to all files on the system. GRUB 2 is the default boot loader for Oracle Linux 7 and is designed to require a password to boot into single-user mode or make modifications to the boot menu.
SRG-OS-000104-GPOS-00051
1 Rule
The Oracle Linux operating system must uniquely identify and must authenticate organizational users (or processes acting on behalf of organizational users) using multifactor authentication.
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-000106-GPOS-00053, SRG-OS-000107-GPOS-00054, SRG-OS-000109-GPOS-00056, SRG-OS-000108-GPOS-00055, SRG-OS-000108-GPOS-00057, SRG-OS-000108-GPOS-00058
SRG-OS-000095-GPOS-00049
1 Rule
The Oracle Linux operating system must not have the rsh-server package installed.
High 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. Operating systems are capable of providing a wide variety of functions and services. Some of the functions and services, provided by default, may not be necessary to support essential organizational operations (e.g., key missions, functions). The rsh-server service provides an unencrypted remote access service that 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 log on using this service, the privileged user password could be compromised.
SRG-OS-000095-GPOS-00049
1 Rule
The Oracle Linux operating system must not have the ypserv package installed.
High Severity
Removing the "ypserv" package decreases the risk of the accidental (or intentional) activation of NIS or NIS+ services.
SRG-OS-000324-GPOS-00125
1 Rule
The Oracle Linux operating system must prevent nonprivileged users from executing privileged functions to include disabling, circumventing, or altering implemented security safeguards/countermeasures.
Medium Severity
Preventing nonprivileged users from executing privileged functions mitigates the risk that unauthorized individuals or processes may gain unnecessary access to information or privileges. Privileged functions include, for example, establishing accounts, performing system integrity checks, or administering cryptographic key management activities. Nonprivileged users are individuals who do not possess appropriate authorizations. Circumventing intrusion detection and prevention mechanisms or malicious code protection mechanisms are examples of privileged functions that require protection from nonprivileged users.
SRG-OS-000363-GPOS-00150
1 Rule
The Oracle Linux operating system must be configured so that a file integrity tool verifies the baseline operating system configuration at least weekly.
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 System Security Manager (ISSM)/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. Satisfies: SRG-OS-000363-GPOS-00150 and SRG-OS-000446-GPOS-00200
SRG-OS-000363-GPOS-00150
1 Rule
The Oracle Linux operating system must be configured so that designated personnel are notified if baseline configurations are changed in an unauthorized manner.
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 System Security Manager (ISSM)/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.
SRG-OS-000366-GPOS-00153
1 Rule
The Oracle Linux operating system must prevent the installation of software, patches, service packs, device drivers, or operating system components from a repository without verification they have been digitally signed using a certificate that is issued by a Certificate Authority (CA) that is recognized and approved by the organization.
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 verifies 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 CA.
SRG-OS-000366-GPOS-00153
1 Rule
The Oracle Linux operating system must prevent the installation of software, patches, service packs, device drivers, or operating system components of local packages without verification they have been digitally signed using a certificate that is issued by a Certificate Authority (CA) that is recognized and approved by the organization.
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 verifies 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 CA.
SRG-OS-000114-GPOS-00059
1 Rule
The Oracle Linux operating system 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-000114-GPOS-00059, SRG-OS-000378-GPOS-00163, SRG-OS-000480-GPOS-00227
SRG-OS-000378-GPOS-00163
1 Rule
The Oracle Linux operating system must be configured so that the Datagram Congestion Control Protocol (DCCP) kernel module is disabled unless required.
Medium Severity
Disabling DCCP protects the system against exploitation of any flaws in the protocol implementation.
SRG-OS-000114-GPOS-00059
1 Rule
The Oracle Linux operating system must disable the file system automounter unless required.
Medium Severity
Automatically mounting file systems permits easy introduction of unknown devices, thereby facilitating malicious activity. Satisfies: SRG-OS-000114-GPOS-00059, SRG-OS-000378-GPOS-00163, SRG-OS-000480-GPOS-00227
SRG-OS-000437-GPOS-00194
1 Rule
The Oracle Linux operating system must remove all software components after updated versions have been installed.
Low Severity
Previous versions of software components that are not removed from the information system after updates have been installed may be exploited by adversaries. Some information technology products may remove older versions of software automatically from the information system.
SRG-OS-000445-GPOS-00199
1 Rule
The Oracle Linux operating system must enable SELinux.
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.
SRG-OS-000480-GPOS-00227
1 Rule
The Oracle Linux operating system must be configured so that the x86 Ctrl-Alt-Delete key sequence is disabled on the command line.
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 the graphical 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-000480-GPOS-00228
1 Rule
The Oracle Linux operating system 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.
SRG-OS-000480-GPOS-00227
1 Rule
The Oracle Linux operating system must be a vendor supported release.
High Severity
An operating system release is considered "supported" if the vendor continues to provide security patches for the product. With an unsupported release, it will not be possible to resolve security issues discovered in the system software.
SRG-OS-000480-GPOS-00227
1 Rule
The Oracle Linux operating system security patches and updates must be installed and up to date.
Medium Severity
Timely patching is critical for maintaining the operational availability, confidentiality, and integrity of information technology (IT) systems. However, failure to keep operating system and application software patched is a common mistake made by IT professionals. New patches are released daily, and it is often difficult for even experienced System Administrators to keep abreast of all the new patches. When new weaknesses in an operating system exist, patches are usually made available by the vendor to resolve the problems. 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
The Oracle Linux operating system must not have unnecessary 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-000104-GPOS-00051
1 Rule
The Oracle Linux operating system must be configured so that all Group Identifiers (GIDs) referenced in the /etc/passwd file are defined in the /etc/group file.
Low Severity
If a user is assigned the GID of a group not existing 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-000480-GPOS-00227
1 Rule
The Oracle Linux operating system must be configured so that the root account must be the only account having unrestricted access to the system.
High Severity
If an account other than root also has a User Identifier (UID) of "0", it has root authority, giving that account unrestricted access to the entire operating system. Multiple accounts with a UID of "0" afford an opportunity for potential intruders to guess a password for a privileged account.
SRG-OS-000480-GPOS-00227
1 Rule
The Oracle Linux operating system must be configured so that all files and directories 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 un-owned files.
SRG-OS-000480-GPOS-00227
1 Rule
The Oracle Linux operating system must be configured so that all files and directories 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
The Oracle Linux operating system must be configured so that all local interactive user accounts, upon creation, are assigned a home directory.
Medium Severity
If local interactive users are not assigned a valid home directory, there is no place for the storage and control of owned files.
SRG-OS-000480-GPOS-00227
1 Rule
The Oracle Linux operating system must be configured so that all local interactive users have a home directory assigned and defined 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. In addition, 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-00227
1 Rule
The Oracle Linux operating system must be configured so that all local interactive user home directories 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-00227
1 Rule
The Oracle Linux operating system must be configured so that all local interactive user home directories are owned by their respective users.
Medium Severity
If a local interactive user does not own their home directory, unauthorized users could access or modify the user's files, and the users may not be able to access their own files.
SRG-OS-000480-GPOS-00227
1 Rule
The Oracle Linux operating system must be configured so that all local interactive user home directories are group-owned by the home directory owners primary group.
Medium Severity
If the Group Identifier (GID) of a local interactive user's home directory is not the same as the primary GID of the user, this would allow unauthorized access to the user's files, and users that share the same group may not be able to access files that they legitimately should.
SRG-OS-000480-GPOS-00227
1 Rule
The Oracle Linux operating system must be configured so that all files and directories contained in local interactive user home directories 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 un-owned files.
SRG-OS-000480-GPOS-00227
1 Rule
The Oracle Linux operating system must be configured so that all files and directories contained in local interactive user home directories are group-owned by a group of which the home directory owner is a member.
Medium Severity
If a local interactive user's files are group-owned by a group of which the user is not a member, unintended users may be able to access them.
SRG-OS-000480-GPOS-00227
1 Rule
The Oracle Linux operating system must be configured so that all files and directories contained in local interactive user home directories have a mode of 0750 or less permissive.
Medium Severity
If a local interactive user files have excessive permissions, unintended users may be able to access or modify them.
SRG-OS-000480-GPOS-00227
1 Rule
The Oracle Linux operating system must be configured so that all local initialization files for interactive users are owned by the home directory user or root.
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.
SRG-OS-000480-GPOS-00227
1 Rule
The Oracle Linux operating system must be configured so that all local initialization files for local interactive users are be group-owned by the users primary group or root.
Medium Severity
Local initialization files for interactive users are used to configure the user's shell environment upon logon. Malicious modification of these files could compromise accounts upon logon.
SRG-OS-000480-GPOS-00227
1 Rule
The Oracle Linux operating system must be configured so that all local initialization files 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.
SRG-OS-000480-GPOS-00227
1 Rule
The Oracle Linux operating system must be configured so that all local interactive user initialization files executable search paths contain only paths that resolve to 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 user's 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-00227
1 Rule
The Oracle Linux operating system must be configured so that local initialization files do 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
The Oracle Linux operating system 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
The Oracle Linux operating system must be configured so that file systems containing user home directories are mounted to prevent files with the setuid and setgid bit set from being executed.
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 unprivileged users to attain unauthorized administrative access.
SRG-OS-000480-GPOS-00227
1 Rule
The Oracle Linux operating system 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 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 unprivileged users to attain unauthorized administrative access.
SRG-OS-000480-GPOS-00227
1 Rule
The Oracle Linux operating system must prevent files with the setuid and setgid bit set from being executed on file systems that are being 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 unprivileged users to attain unauthorized administrative access.
SRG-OS-000480-GPOS-00227
1 Rule
The Oracle Linux operating system must prevent binary files from being executed on file systems that are being imported via Network File System (NFS).
Medium Severity
The "noexec" mount option causes the system not to 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 unprivileged users to attain unauthorized administrative access.
SRG-OS-000368-GPOS-00154
1 Rule
The Oracle Linux operating system must mount /dev/shm with secure options.
Low 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 unprivileged users to attain unauthorized administrative access. 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 unprivileged users to attain unauthorized administrative access. 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 unprivileged users to attain unauthorized administrative access.
SRG-OS-000480-GPOS-00227
1 Rule
The Oracle Linux operating system must be configured so that all world-writable directories are group-owned by root, sys, bin, or an application group.
Medium Severity
If a world-writable directory is not group-owned by root, sys, bin, or an application Group Identifier (GID), 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-000480-GPOS-00227
1 Rule
The Oracle Linux operating system must set the umask value to 077 for all local interactive user accounts.
Medium Severity
The umask controls the default access mode assigned to newly created files. A umask of 077 limits new files to mode 700 or less permissive. Although umask can be represented as a four-digit number, the first digit representing special access modes is typically ignored or required to be "0". This requirement applies to the globally configured system defaults and the local interactive user defaults for each account on the system.
SRG-OS-000480-GPOS-00227
1 Rule
The Oracle Linux operating system must have cron logging implemented.
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
The Oracle Linux operating system must be configured so that the cron.allow file, if it exists, is owned by root.
Medium Severity
If the owner of the "cron.allow" file is not set to root, the possibility exists for an unauthorized user to view or to edit sensitive information.
SRG-OS-000480-GPOS-00227
1 Rule
The Oracle Linux operating system must be configured so that the cron.allow file, if it exists, is group-owned by root.
Medium Severity
If the group owner of the "cron.allow" file is not set to root, sensitive information could be viewed or edited by unauthorized users.
SRG-OS-000480-GPOS-00227
1 Rule
The Oracle Linux operating system must disable Kernel core dumps unless needed.
Medium Severity
Kernel core dumps may contain the full contents of system memory at the time of the crash. Kernel core dumps may 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.
SRG-OS-000480-GPOS-00227
1 Rule
The Oracle Linux operating system must be configured so that a separate file system is used for user home directories (such as /home or an equivalent).
Low Severity
The use of separate file systems for different paths can protect the system from failures resulting from a file system becoming full or failing.
SRG-OS-000480-GPOS-00227
1 Rule
The Oracle Linux operating system must use a separate file system for /var.
Low Severity
The use of separate file systems for different paths can protect the system from failures resulting from a file system becoming full or failing.
SRG-OS-000341-GPOS-00132
1 Rule
The Oracle Linux operating system must use a separate file system for the system audit data path large enough to hold at least one week of audit data.
Low Severity
The use of separate file systems for different paths can protect the system from failures resulting from a file system becoming full or failing.
SRG-OS-000480-GPOS-00227
1 Rule
The Oracle Linux operating system must use a separate file system for /tmp (or equivalent).
Low Severity
The use of separate file systems for different paths can protect the system from failures resulting from a file system becoming full or failing.
SRG-OS-000033-GPOS-00014
1 Rule
The Oracle Linux operating system must implement NIST FIPS-validated cryptography for the following: to provision digital signatures, to generate cryptographic hashes, and to protect data requiring data-at-rest protections in accordance with applicable federal laws, Executive Orders, directives, policies, regulations, and standards.
High Severity
Use of weak or untested encryption algorithms undermines the purposes of using encryption to protect data. The operating system must implement cryptographic modules that adhere to the higher standards approved by the federal government to ensure they have been tested and validated. Satisfies: SRG-OS-000033-GPOS-00014, SRG-OS-000185-GPOS-00079, SRG-OS-000396-GPOS-00176, SRG-OS-000405-GPOS-00184, SRG-OS-000478-GPOS-00223
SRG-OS-000480-GPOS-00227
1 Rule
The Oracle Linux operating system must be configured so that the file integrity tool is configured to verify Access Control Lists (ACLs).
Low Severity
ACLs can provide permissions beyond those permitted through the file mode and must be verified by file integrity tools.
SRG-OS-000480-GPOS-00227
1 Rule
The Oracle Linux operating system must be configured so that the file integrity tool is configured to verify extended attributes.
Low Severity
Extended attributes in file systems are used to contain arbitrary data and file metadata with security implications.
SRG-OS-000480-GPOS-00227
1 Rule
The Oracle Linux operating system must use a file integrity tool that is configured to use FIPS 140-2 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 140-2 approved cryptographic hashes. The Oracle Linux operating system installation media ships with an optional file integrity tool called Advanced Intrusion Detection Environment (AIDE). AIDE is highly configurable at install time. This requirement assumes the "aide.conf" file is under the "/etc" directory.
SRG-OS-000364-GPOS-00151
1 Rule
The Oracle Linux operating system must not allow removable media to be used as the boot loader unless approved.
Medium Severity
Malicious users with removable boot media can gain access to a system configured to use removable media as the boot loader. If removable media is designed to be used as the boot loader, the requirement must be documented with the information system security officer (ISSO).
SRG-OS-000095-GPOS-00049
1 Rule
The Oracle Linux operating system must not have the telnet-server package installed.
High 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. Operating systems are capable of providing a wide variety of functions and services. Some of the functions and services, provided by default, may not be necessary to support essential organizational operations (e.g., key missions, functions). Examples of non-essential capabilities include, but are not limited to, games, software packages, tools, and demonstration software not related to requirements or providing a wide array of functionality not required for every mission, but which cannot be disabled.
SRG-OS-000038-GPOS-00016
1 Rule
The Oracle Linux operating system must be configured so that auditing is configured to produce records containing information to establish what type of events occurred, where the events occurred, the source of the events, and the outcome of the events. These audit records must also identify individual identities of group account users.
Medium Severity
Without establishing what type of events occurred, 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 the operating system audit logs provides a means of investigating an attack; recognizing resource utilization or capacity thresholds, or identifying an improperly configured operating system. Satisfies: SRG-OS-000038-GPOS-00016, SRG-OS-000039-GPOS-00017, SRG-OS-000042-GPOS-00021, SRG-OS-000254-GPOS-00095, SRG-OS-000365-GPOS-00152, SRG-OS-000255-GPOS-00096
SRG-OS-000046-GPOS-00022
1 Rule
The Oracle Linux operating system must shut down upon audit processing failure, unless availability is an overriding concern. If availability is a concern, the system must alert the designated staff (System Administrator [SA] and Information System Security Officer [ISSO] 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. Satisfies: SRG-OS-000046-GPOS-00022, SRG-OS-000047-GPOS-00023
SRG-OS-000342-GPOS-00133
1 Rule
The Oracle Linux operating system must be configured to off-load audit logs onto a different system or storage media from the system being audited.
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. One method of off-loading audit logs in Oracle Linux is with the use of the audisp-remote dameon. Without the configuration of the "au-remote" plugin, the audisp-remote daemon will not off load the logs from the system being audited. Satisfies: SRG-OS-000342-GPOS-00133, SRG-OS-000479-GPOS-00224
SRG-OS-000342-GPOS-00133
1 Rule
The Oracle Linux operating system must take appropriate action when the remote logging buffer is full.
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. One method of off-loading audit logs in Oracle Linux is with the use of the audisp-remote dameon. When the remote buffer is full, audit logs will not be collected and sent to the central log server. Satisfies: SRG-OS-000342-GPOS-00133, SRG-OS-000479-GPOS-00224
SRG-OS-000342-GPOS-00133
1 Rule
The Oracle Linux operating system must label all off-loaded audit logs before sending them to the central log server.
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. One method of off-loading audit logs in Oracle Linux is with the use of the audisp-remote dameon. When audit logs are not labeled 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. Satisfies: SRG-OS-000342-GPOS-00133, SRG-OS-000479-GPOS-00224
SRG-OS-000342-GPOS-00133
1 Rule
The Oracle Linux operating system must off-load audit records onto a different system or media from the system being audited.
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. Satisfies: SRG-OS-000342-GPOS-00133, SRG-OS-000479-GPOS-00224
SRG-OS-000342-GPOS-00133
1 Rule
The Oracle Linux operating system must encrypt the transfer of audit records off-loaded onto a different system or media from the system being audited.
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. Satisfies: SRG-OS-000342-GPOS-00133, SRG-OS-000479-GPOS-00224
SRG-OS-000342-GPOS-00133
1 Rule
The Oracle Linux operating system must be configured so that the audit system takes appropriate action when the audit storage volume is full.
Medium Severity
Taking appropriate action in case of a filled audit storage volume will minimize the possibility of losing audit records. One method of off-loading audit logs in Oracle Linux is with the use of the audisp-remote dameon.
SRG-OS-000342-GPOS-00133
1 Rule
The Oracle Linux operating system must be configured so that the audit system takes appropriate action when there is an error sending audit records to a remote system.
Medium Severity
Taking appropriate action when there is an error sending audit records to a remote system will minimize the possibility of losing audit records. One method of off-loading audit logs in Oracle Linux is with the use of the audisp-remote dameon.
SRG-OS-000343-GPOS-00134
1 Rule
The Oracle Linux operating system must initiate an action to notify the System Administrator (SA) and Information System Security Officer (ISSO), at a minimum, 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 utilization, they are unable to plan for audit record storage capacity expansion.
SRG-OS-000343-GPOS-00134
1 Rule
The Oracle Linux operating system must immediately notify the System Administrator (SA) and Information System Security Officer (ISSO) (at a minimum) via email when the threshold for the repository maximum audit record storage capacity is reached.
Medium Severity
If security personnel are not notified immediately when the threshold for the repository maximum audit record storage capacity is reached, they are unable to expand the audit record storage capacity before records are lost.
SRG-OS-000343-GPOS-00134
1 Rule
The Oracle Linux operating system must immediately notify the System Administrator (SA) and Information System Security Officer (ISSO) (at a minimum) when the threshold for the repository maximum audit record storage capacity is reached.
Medium Severity
If security personnel are not notified immediately when the threshold for the repository maximum audit record storage capacity is reached, they are unable to expand the audit record storage capacity before records are lost.
SRG-OS-000327-GPOS-00127
1 Rule
The Oracle Linux operating system must audit all executions of privileged functions.
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.
SRG-OS-000064-GPOS-00033
1 Rule
The Oracle Linux operating system must audit all uses of the chown, fchown, fchownat, and lchown syscalls.
Medium Severity
Without generating audit records that are 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 that is 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 syscall made by all programs on the system. Therefore, it is very important to use syscall 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 syscalls into one rule whenever possible. Satisfies: SRG-OS-000064-GPOS-00033, SRG-OS-000392-GPOS-00172, SRG-OS-000458-GPOS-00203, SRG-OS-000474-GPOS-00219
SRG-OS-000458-GPOS-00203
1 Rule
The Oracle Linux operating system must audit all uses of the chmod, fchmod, and fchmodat syscalls.
Medium Severity
Without generating audit records that are 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 that is 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 syscall made by all programs on the system. Therefore, it is very important to use syscall 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 syscalls into one rule whenever possible. Satisfies: SRG-OS-000458-GPOS-00203, SRG-OS-000392-GPOS-00172, SRG-OS-000064-GPOS-00033
SRG-OS-000458-GPOS-00203
1 Rule
The Oracle Linux operating system must audit all uses of the setxattr, fsetxattr, lsetxattr, removexattr, fremovexattr, and lremovexattr syscalls.
Medium Severity
Without generating audit records that are 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 that is 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 syscall made by all programs on the system. Therefore, it is very important to use syscall 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 syscalls into one rule whenever possible. Satisfies: SRG-OS-000458-GPOS-00203, SRG-OS-000392-GPOS-00172, SRG-OS-000064-GPOS-00033
SRG-OS-000064-GPOS-00033
1 Rule
The Oracle Linux operating system must audit all uses of the creat, open, openat, open_by_handle_at, truncate, and ftruncate syscalls.
Medium Severity
Without generating audit records that are 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 that is 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 syscall made by all programs on the system. Therefore, it is very important to use syscall 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 syscalls into one rule whenever possible. Satisfies: SRG-OS-000064-GPOS-00033, SRG-OS-000458-GPOS-00203, SRG-OS-000461-GPOS-00205, SRG-OS-000392-GPOS-00172
SRG-OS-000392-GPOS-00172
1 Rule
The Oracle Linux operating system must audit all uses 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 that is 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. Satisfies: SRG-OS-000392-GPOS-00172, SRG-OS-000463-GPOS-00207, SRG-OS-000465-GPOS-00209
SRG-OS-000392-GPOS-00172
1 Rule
The Oracle Linux operating system must audit all uses 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 that is 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. Satisfies: SRG-OS-000392-GPOS-00172, SRG-OS-000463-GPOS-00207, SRG-OS-000465-GPOS-00209
SRG-OS-000392-GPOS-00172
1 Rule
The Oracle Linux operating system must audit all uses 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 that is 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. Satisfies: SRG-OS-000392-GPOS-00172, SRG-OS-000463-GPOS-00207, SRG-OS-000465-GPOS-00209
SRG-OS-000392-GPOS-00172
1 Rule
The Oracle Linux operating system must audit all uses 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 that is 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. Satisfies: SRG-OS-000392-GPOS-00172, SRG-OS-000463-GPOS-00207, SRG-OS-000465-GPOS-00209
SRG-OS-000392-GPOS-00172
1 Rule
The Oracle Linux operating system must generate audit records for all unsuccessful account access events.
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). Satisfies: SRG-OS-000392-GPOS-00172, SRG-OS-000470-GPOS-00214, SRG-OS-000473-GPOS-00218
SRG-OS-000392-GPOS-00172
1 Rule
The Oracle Linux operating system must generate audit records for all successful account access events.
Medium Severity
Without generating audit records that 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). Satisfies: SRG-OS-000392-GPOS-00172, SRG-OS-000470-GPOS-00214, SRG-OS-000473-GPOS-00218
SRG-OS-000042-GPOS-00020
1 Rule
The Oracle Linux operating system must audit all uses of the passwd command.
Medium Severity
Reconstruction of harmful events or forensic analysis is not possible if audit records do not contain enough information. At a minimum, the organization must audit the full-text recording of privileged password commands. The organization must maintain audit trails in sufficient detail to reconstruct events to determine the cause and impact of compromise. When a user logs on, the auid is set to the uid of the account that is 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. Satisfies: SRG-OS-000042-GPOS-00020, SRG-OS-000392-GPOS-00172, SRG-OS-000471-GPOS-00215
SRG-OS-000042-GPOS-00020
1 Rule
The Oracle Linux operating system must audit all uses of the unix_chkpwd command.
Medium Severity
Reconstruction of harmful events or forensic analysis is not possible if audit records do not contain enough information. At a minimum, the organization must audit the full-text recording of privileged password commands. The organization must maintain audit trails in sufficient detail to reconstruct events to determine the cause and impact of compromise. When a user logs on, the auid is set to the uid of the account that is 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. Satisfies: SRG-OS-000042-GPOS-00020, SRG-OS-000392-GPOS-00172, SRG-OS-000471-GPOS-00215
SRG-OS-000042-GPOS-00020
1 Rule
The Oracle Linux operating system must audit all uses of the gpasswd command.
Medium Severity
Reconstruction of harmful events or forensic analysis is not possible if audit records do not contain enough information. At a minimum, the organization must audit the full-text recording of privileged password commands. The organization must maintain audit trails in sufficient detail to reconstruct events to determine the cause and impact of compromise. When a user logs on, the auid is set to the uid of the account that is 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. Satisfies: SRG-OS-000042-GPOS-00020, SRG-OS-000392-GPOS-00172, SRG-OS-000471-GPOS-00215
SRG-OS-000042-GPOS-00020
1 Rule
The Oracle Linux operating system must audit all uses of the chage command.
Medium Severity
Reconstruction of harmful events or forensic analysis is not possible if audit records do not contain enough information. At a minimum, the organization must audit the full-text recording of privileged password commands. The organization must maintain audit trails in sufficient detail to reconstruct events to determine the cause and impact of compromise. When a user logs on, the auid is set to the uid of the account that is 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. Satisfies: SRG-OS-000042-GPOS-00020, SRG-OS-000392-GPOS-00172, SRG-OS-000471-GPOS-00215
SRG-OS-000042-GPOS-00020
1 Rule
The Oracle Linux operating system must audit all uses of the userhelper command.
Medium Severity
Reconstruction of harmful events or forensic analysis is not possible if audit records do not contain enough information. At a minimum, the organization must audit the full-text recording of privileged password commands. The organization must maintain audit trails in sufficient detail to reconstruct events to determine the cause and impact of compromise. When a user logs on, the auid is set to the uid of the account that is 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. Satisfies: SRG-OS-000042-GPOS-00020, SRG-OS-000392-GPOS-00172, SRG-OS-000471-GPOS-00215
SRG-OS-000037-GPOS-00015
1 Rule
The Oracle Linux operating system must audit all uses of the su command.
Medium Severity
Reconstruction of harmful events or forensic analysis is not possible if audit records do not contain enough information. At a minimum, the organization must audit the full-text recording of privileged access commands. The organization must maintain audit trails in sufficient detail to reconstruct events to determine the cause and impact of compromise. When a user logs on, the auid is set to the uid of the account that is 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. Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215
SRG-OS-000037-GPOS-00015
1 Rule
The Oracle Linux operating system must audit all uses of the sudo command.
Medium Severity
Reconstruction of harmful events or forensic analysis is not possible if audit records do not contain enough information. At a minimum, the organization must audit the full-text recording of privileged access commands. The organization must maintain audit trails in sufficient detail to reconstruct events to determine the cause and impact of compromise. When a user logs on, the auid is set to the uid of the account that is 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. Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215
SRG-OS-000037-GPOS-00015
1 Rule
The Oracle Linux operating system must audit all uses of the sudoers file and all files in the /etc/sudoers.d/ directory.
Medium Severity
Reconstruction of harmful events or forensic analysis is not possible if audit records do not contain enough information. At a minimum, the organization must audit the full-text recording of privileged access commands. The organization must maintain audit trails in sufficient detail to reconstruct events to determine the cause and impact of compromise. Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215
SRG-OS-000037-GPOS-00015
1 Rule
The Oracle Linux operating system must audit all uses of the newgrp command.
Medium Severity
Reconstruction of harmful events or forensic analysis is not possible if audit records do not contain enough information. At a minimum, the organization must audit the full-text recording of privileged access commands. The organization must maintain audit trails in sufficient detail to reconstruct events to determine the cause and impact of compromise. When a user logs on, the auid is set to the uid of the account that is 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. Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215
SRG-OS-000037-GPOS-00015
1 Rule
The Oracle Linux operating system must audit all uses of the chsh command.
Medium Severity
Reconstruction of harmful events or forensic analysis is not possible if audit records do not contain enough information. At a minimum, the organization must audit the full-text recording of privileged access commands. The organization must maintain audit trails in sufficient detail to reconstruct events to determine the cause and impact of compromise. When a user logs on, the auid is set to the uid of the account that is 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. Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215
SRG-OS-000042-GPOS-00020
1 Rule
The Oracle Linux operating system must audit all uses of the mount command and syscall.
Medium Severity
Reconstruction of harmful events or forensic analysis is not possible if audit records do not contain enough information. At a minimum, the organization must audit the full-text recording of privileged mount commands. The organization must maintain audit trails in sufficient detail to reconstruct events to determine the cause and impact of compromise. When a user logs on, the auid is set to the uid of the account that is 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. Satisfies: SRG-OS-000042-GPOS-00020, SRG-OS-000392-GPOS-00172
SRG-OS-000042-GPOS-00020
1 Rule
The Oracle Linux operating system must audit all uses of the umount command.
Medium Severity
Reconstruction of harmful events or forensic analysis is not possible if audit records do not contain enough information. At a minimum, the organization must audit the full-text recording of privileged mount commands. The organization must maintain audit trails in sufficient detail to reconstruct events to determine the cause and impact of compromise. When a user logs on, the auid is set to the uid of the account that is 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. Satisfies: SRG-OS-000042-GPOS-00020, SRG-OS-000392-GPOS-00172
SRG-OS-000042-GPOS-00020
1 Rule
The Oracle Linux operating system must audit all uses of the postdrop command.
Medium Severity
Reconstruction of harmful events or forensic analysis is not possible if audit records do not contain enough information. At a minimum, the organization must audit the full-text recording of privileged postfix commands. The organization must maintain audit trails in sufficient detail to reconstruct events to determine the cause and impact of compromise. When a user logs on, the auid is set to the uid of the account that is 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. Satisfies: SRG-OS-000042-GPOS-00020, SRG-OS-000392-GPOS-00172
SRG-OS-000042-GPOS-00020
1 Rule
The Oracle Linux operating system must audit all uses of the postqueue command.
Medium Severity
Reconstruction of harmful events or forensic analysis is not possible if audit records do not contain enough information. At a minimum, the organization must audit the full-text recording of privileged postfix commands. The organization must maintain audit trails in sufficient detail to reconstruct events to determine the cause and impact of compromise. When a user logs on, the auid is set to the uid of the account that is 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. Satisfies: SRG-OS-000042-GPOS-00020, SRG-OS-000392-GPOS-00172
SRG-OS-000042-GPOS-00020
1 Rule
The Oracle Linux operating system must audit all uses of the ssh-keysign command.
Medium Severity
Reconstruction of harmful events or forensic analysis is not possible if audit records do not contain enough information. At a minimum, the organization must audit the full-text recording of privileged ssh commands. The organization must maintain audit trails in sufficient detail to reconstruct events to determine the cause and impact of compromise. When a user logs on, the auid is set to the uid of the account that is 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. Satisfies: SRG-OS-000042-GPOS-00020, SRG-OS-000392-GPOS-00172, SRG-OS-000471-GPOS-00215
SRG-OS-000042-GPOS-00020
1 Rule
The Oracle Linux operating system must audit all uses of the crontab command.
Medium Severity
Reconstruction of harmful events or forensic analysis is not possible if audit records do not contain enough information. At a minimum, the organization must audit the full-text recording of privileged commands. The organization must maintain audit trails in sufficient detail to reconstruct events to determine the cause and impact of compromise. When a user logs on, the auid is set to the uid of the account that is 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. Satisfies: SRG-OS-000042-GPOS-00020, SRG-OS-000392-GPOS-00172, SRG-OS-000471-GPOS-00215
SRG-OS-000471-GPOS-00215
1 Rule
The Oracle Linux operating system must audit all uses 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. When a user logs on, the auid is set to the uid of the account that is 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.
SRG-OS-000471-GPOS-00216
1 Rule
The Oracle Linux operating system must audit all uses of the create_module syscall.
Medium Severity
Without generating audit records that are 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). Satisfies: SRG-OS-000471-GPOS-00216, SRG-OS-000477-GPOS-00222
SRG-OS-000471-GPOS-00216
1 Rule
The Oracle Linux operating system must audit all uses of the init_module and finit_module syscalls.
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). The system call rules are loaded into a matching engine that intercepts each syscall made by all programs on the system. Therefore, it is very important to use syscall 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 syscalls into one rule whenever possible. Satisfies: SRG-OS-000471-GPOS-00216, SRG-OS-000477-GPOS-00222
SRG-OS-000471-GPOS-00216
1 Rule
The Oracle Linux operating system must audit all uses of the delete_module syscall.
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). Satisfies: SRG-OS-000471-GPOS-00216, SRG-OS-000477-GPOS-00222
SRG-OS-000471-GPOS-00216
1 Rule
The Oracle Linux operating system 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 that is 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. Satisfies: SRG-OS-000471-GPOS-00216, SRG-OS-000477-GPOS-00222
SRG-OS-000004-GPOS-00004
1 Rule
The Oracle Linux operating system must generate audit records for all account creations, modifications, disabling, and termination events that affect /etc/passwd.
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). Satisfies: SRG-OS-000004-GPOS-00004, SRG-OS-000239-GPOS-00089, SRG-OS-000240-GPOS-00090, SRG-OS-000241-GPOS-00091, SRG-OS-000303-GPOS-00120, SRG-OS-000476-GPOS-00221
SRG-OS-000004-GPOS-00004
1 Rule
The Oracle Linux operating system must generate audit records for all account creations, modifications, disabling, and termination events that affect /etc/group.
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).
SRG-OS-000004-GPOS-00004
1 Rule
The Oracle Linux operating system must generate audit records for all account creations, modifications, disabling, and termination events that affect /etc/gshadow.
Medium Severity
Without generating audit 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).
SRG-OS-000004-GPOS-00004
1 Rule
The Oracle Linux operating system must generate audit records for all account creations, modifications, disabling, and termination events that affect /etc/shadow.
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).
SRG-OS-000004-GPOS-00004
1 Rule
The Oracle Linux operating system must generate audit records for all account creations, modifications, disabling, and termination events that affect /etc/security/opasswd.
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).
SRG-OS-000466-GPOS-00210
1 Rule
The Oracle Linux operating system must audit all uses of the unlink, unlinkat, rename, renameat, and rmdir syscalls.
Medium Severity
If the system is not configured to audit certain activities and write them to an audit log, it is more difficult to detect and track system compromises and damages incurred during a system compromise. When a user logs on, the auid is set to the uid of the account that is 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 syscall made by all programs on the system. Therefore, it is very important to use syscall 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 syscalls into one rule whenever possible. Satisfies: SRG-OS-000466-GPOS-00210, SRG-OS-000467-GPOS-00211, SRG-OS-000468-GPOS-00212, SRG-OS-000392-GPOS-00172
SRG-OS-000480-GPOS-00227
1 Rule
The Oracle Linux operating system must send rsyslog output to a log aggregation server.
Medium Severity
Sending rsyslog output to another system ensures that the logs cannot be removed or modified in the event that the system is compromised or has a hardware failure.
SRG-OS-000480-GPOS-00227
1 Rule
The Oracle Linux operating system 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 in to 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 ISSO.
SRG-OS-000480-GPOS-00227
1 Rule
The Oracle Linux operating system must use a virus scan program.
High Severity
Virus scanning software can be used to protect a system from penetration from computer viruses and to limit their spread through intermediate systems. The virus scanning software should be configured to perform scans dynamically on accessed files. If this capability is not available, the system must be configured to scan, at a minimum, all altered files on the system on a daily basis. If the system processes inbound SMTP mail, the virus scanner must be configured to scan all received mail.
SRG-OS-000027-GPOS-00008
1 Rule
The Oracle Linux operating system must limit the number of concurrent sessions to 10 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 utilize an operating system. Limiting the number of allowed users and sessions per user is helpful in reducing the risks related to 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 on mission needs and the operational environment for each system.
SRG-OS-000096-GPOS-00050
1 Rule
The Oracle Linux operating system must be configured to prohibit or restrict the use of functions, ports, protocols, and/or services, as defined in the Ports, Protocols, and Services Management Component Local Service Assessment (PPSM CLSA) and vulnerability assessments.
Medium Severity
In order to prevent unauthorized connection of devices, unauthorized transfer of information, or unauthorized tunneling (i.e., embedding of data types within data types), organizations must disable or restrict unused or unnecessary physical and logical ports/protocols on information systems. Operating systems are capable of providing a wide variety of functions and services. Some of the functions and services provided by default may not be necessary to support essential organizational operations. Additionally, it is sometimes convenient to provide multiple services from a single component (e.g., VPN and IPS); however, doing so increases risk over limiting the services provided by any one component. To support the requirements and principles of least functionality, the operating system must support the organizational requirements, providing only essential capabilities and limiting the use of ports, protocols, and/or services to only those required, authorized, and approved to conduct official business or to address authorized quality of life issues. Satisfies: SRG-OS-000096-GPOS-00050, SRG-OS-000297-GPOS-00115
SRG-OS-000033-GPOS-00014
1 Rule
The Oracle Linux 7 operating system must implement DoD-approved encryption to protect the confidentiality of SSH connections.
Medium Severity
Unapproved mechanisms for authentication to the cryptographic module are not verified, and therefore cannot be relied upon to provide confidentiality or integrity, resulting in the compromise of DoD data. Operating systems using encryption are required to use FIPS-compliant mechanisms for authenticating to cryptographic modules. FIPS 140-2 is the current standard for validating mechanisms used to access cryptographic modules utilize authentication that meets DoD requirements. This allows for Security Levels 1, 2, 3, or 4 for use on a general-purpose computing system. The system will attempt to use the first cipher 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 cipher available to secure the SSH connection. Satisfies: SRG-OS-000033-GPOS-00014, SRG-OS-000120-GPOS-00061, SRG-OS-000125-GPOS-00065, SRG-OS-000250-GPOS-00093, SRG-OS-000393-GPOS-00173,SRG-OS-000394-GPOS-00174
SRG-OS-000163-GPOS-00072
1 Rule
The Oracle Linux operating system must be configured so that all network connections associated with a communication session are terminated at the end of the session or after 15 minutes of inactivity from the user at a command prompt, except to fulfill documented and validated mission requirements.
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-000023-GPOS-00006
1 Rule
The Oracle Linux operating system must display the Standard Mandatory DoD Notice and Consent Banner immediately prior to, or as part of, remote access logon prompts.
Medium Severity
Display of a standardized and approved use notification before granting access to the publicly accessible 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." Satisfies: SRG-OS-000023-GPOS-00006, SRG-OS-000024-GPOS-00007 , SRG-OS-000228-GPOS-00088
SRG-OS-000250-GPOS-00093
1 Rule
The Oracle Linux operating system must implement cryptography to protect the integrity of Lightweight Directory Access Protocol (LDAP) authentication communications.
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 key used to generate the hash.
SRG-OS-000250-GPOS-00093
1 Rule
The Oracle Linux operating system must implement cryptography to protect the integrity of Lightweight Directory Access Protocol (LDAP) communications.
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 key used to generate the hash.
SRG-OS-000250-GPOS-00093
1 Rule
The Oracle Linux operating system must implement cryptography to protect the integrity of Lightweight Directory Access Protocol (LDAP) communications.
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 key used to generate the hash.
SRG-OS-000433-GPOS-00193
1 Rule
The Oracle Linux operating system must implement virtual address space randomization.
Medium Severity
Address space layout randomization (ASLR) makes it more difficult for an attacker to predict the location of attack code introduced into a process's address space during an attempt at exploitation. Additionally, ASLR also makes it more difficult for an attacker to know the location of existing code in order to repurpose it using return-oriented programming (ROP) techniques.
SRG-OS-000423-GPOS-00187
1 Rule
The Oracle Linux operating system must be configured so that all networked systems have SSH 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, logical means (cryptography) do not have to be employed, and vice versa. Satisfies: SRG-OS-000423-GPOS-00187, SRG-OS-000424-GPOS-00188, SRG-OS-000425-GPOS-00189, SRG-OS-000426-GPOS-00190
SRG-OS-000423-GPOS-00187
1 Rule
The Oracle Linux operating system must be configured so that all networked systems use SSH for confidentiality and integrity of transmitted and received information as well as information during preparation 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-000423-GPOS-00187, SRG-OS-000424-GPOS-00188, SRG-OS-000425-GPOS-00189, SRG-OS-000426-GPOS-00190
SRG-OS-000163-GPOS-00072
1 Rule
The Oracle Linux operating system 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-000163-GPOS-00072, SRG-OS-000279-GPOS-00109
SRG-OS-000480-GPOS-00227
1 Rule
The Oracle Linux operating system must be configured so that the SSH daemon does not allow authentication using RSA rhosts authentication.
Medium Severity
Configuring this setting for the SSH daemon provides additional assurance that remote logon via SSH will require a password, even in the event of misconfiguration elsewhere.
SRG-OS-000163-GPOS-00072
1 Rule
The Oracle Linux operating system must be configured so that all network connections associated with SSH traffic terminate after 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-000163-GPOS-00072, SRG-OS-000279-GPOS-00109
SRG-OS-000480-GPOS-00227
1 Rule
The Oracle Linux operating system must be configured so that the SSH daemon does not allow authentication using rhosts authentication.
Medium Severity
Configuring this setting for the SSH daemon provides additional assurance that remote logon via SSH will require a password, even in the event of misconfiguration elsewhere.
SRG-OS-000480-GPOS-00227
1 Rule
The Oracle Linux operating system must display the date and time of the last successful account logon upon an SSH logon.
Medium Severity
Providing users with feedback on when account accesses via SSH last occurred facilitates user recognition and reporting of unauthorized account use.
SRG-OS-000480-GPOS-00227
1 Rule
The Oracle Linux operating system 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 on directly as root. In addition, logging on with a user-specific account provides individual accountability of actions performed on the system.
SRG-OS-000480-GPOS-00227
1 Rule
The Oracle Linux operating system must be configured so that the SSH daemon does not allow authentication using known hosts authentication.
Medium Severity
Configuring this setting for the SSH daemon provides additional assurance that remote logon via SSH will require a password, even in the event of misconfiguration elsewhere.
SRG-OS-000074-GPOS-00042
1 Rule
The Oracle Linux operating system must be configured so that the SSH daemon is configured to only use the SSHv2 protocol.
High Severity
SSHv1 is an insecure implementation of the SSH protocol and has many well-known vulnerability exploits. Exploits of the SSH daemon could provide immediate root access to the system. Satisfies: SRG-OS-000074-GPOS-00042, SRG-OS-000480-GPOS-00227
SRG-OS-000250-GPOS-00093
1 Rule
The Oracle Linux operating system must be configured so that the SSH daemon is configured to only use Message Authentication Codes (MACs) employing FIPS 140-2 approved cryptographic hash algorithms.
Medium Severity
DoD information systems are required to use FIPS 140-2 approved cryptographic hash functions. The only SSHv2 hash algorithm meeting this requirement is SHA. The system will attempt to use the first hash 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 hash available to secure the SSH connection.
SRG-OS-000480-GPOS-00227
1 Rule
The Oracle Linux operating system must be configured so that the SSH public host key files 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.
SRG-OS-000480-GPOS-00227
1 Rule
The Oracle Linux operating system must be configured so the SSH private host key files 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-000364-GPOS-00151
1 Rule
The Oracle Linux operating system must be configured so that the SSH daemon does not permit Generic Security Service Application Program Interface (GSSAPI) authentication unless needed.
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. GSSAPI authentication must be disabled unless needed.
SRG-OS-000364-GPOS-00151
1 Rule
The Oracle Linux operating system must be configured so that the SSH daemon does not permit Kerberos authentication unless needed.
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 implementation may then be subject to exploitation. To reduce the attack surface of the system, the Kerberos authentication mechanism within SSH must be disabled for systems not using this capability.
SRG-OS-000480-GPOS-00227
1 Rule
The Oracle Linux operating system must be configured so that the SSH daemon performs strict mode checking of home directory configuration files.
Medium Severity
If other users have access to modify user-specific SSH configuration files, they may be able to log on to the system as another user.
SRG-OS-000480-GPOS-00227
1 Rule
The Oracle Linux operating system must be configured so that the SSH daemon uses privilege separation.
Medium Severity
SSH daemon privilege separation causes the SSH process to drop root privileges when not needed, which would decrease the impact of software vulnerabilities in the unprivileged section.
SRG-OS-000480-GPOS-00227
1 Rule
The Oracle Linux operating system must be configured so that the SSH daemon does not allow compression or only allows 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-000355-GPOS-00143
1 Rule
The Oracle Linux operating system must, for networked systems, synchronize clocks with a server that is synchronized to one of the redundant United States Naval Observatory (USNO) time servers, a time server designated for the appropriate DoD network (NIPRNet/SIPRNet), and/or the Global Positioning System (GPS).
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-000356-GPOS-00144
SRG-OS-000420-GPOS-00186
1 Rule
The Oracle Linux operating system must protect against or limit the effects of Denial of Service (DoS) attacks by validating the operating system is implementing rate-limiting measures on impacted network interfaces.
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 exists 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-000480-GPOS-00227
1 Rule
The Oracle Linux operating system must enable an application firewall, if available.
Medium Severity
Firewalls protect computers from network attacks by blocking or limiting access to open network ports. Application firewalls limit which applications are allowed to communicate over the network. Satisfies: SRG-OS-000480-GPOS-00227, SRG-OS-000480-GPOS-00231, SRG-OS-000480-GPOS-00232
SRG-OS-000480-GPOS-00227
1 Rule
The Oracle Linux operating system must display the date and time of the last successful account logon upon logon.
Low Severity
Providing users with feedback on when account accesses last occurred facilitates user recognition and reporting of unauthorized account use.
SRG-OS-000480-GPOS-00227
1 Rule
The Oracle Linux operating system must not contain .shosts files.
High 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
The Oracle Linux operating system must not contain shosts.equiv files.
High 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
For Oracle Linux operating systems using DNS resolution, at least two name servers must be configured.
Low 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
The Oracle Linux operating system must not forward Internet Protocol version 4 (IPv4) source-routed packets.
Medium Severity
Source-routed packets allow the source of the packet to suggest that 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 IPv4 forwarding is enabled and the system is functioning as a router.
SRG-OS-000480-GPOS-00227
1 Rule
The Oracle Linux operating system must use a reverse-path filter for IPv4 network traffic when possible on all interfaces.
Medium Severity
Enabling reverse path filtering drops packets with invalid source addresses received on the interface. It should 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
The Oracle Linux operating system must use a reverse-path filter for IPv4 network traffic when possible by default.
Medium Severity
Enabling reverse path filtering drops packets with invalid source addresses received on the interface. It should not be used on systems which are routers for complicated networks, but is helpful for end hosts and routers serving small networks.
SRG-OS-000480-GPOS-00227
1 Rule
The Oracle Linux operating system must not forward Internet Protocol version 4 (IPv4) source-routed packets by default.
Medium Severity
Source-routed packets allow the source of the packet to suggest that 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 IPv4 forwarding is enabled and the system is functioning as a router.
SRG-OS-000480-GPOS-00227
1 Rule
The Oracle Linux operating system must not respond to Internet Protocol version 4 (IPv4) 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.
SRG-OS-000480-GPOS-00227
1 Rule
The Oracle Linux operating system must prevent Internet Protocol version 4 (IPv4) Internet Control Message Protocol (ICMP) redirect messages from being accepted.
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.
SRG-OS-000480-GPOS-00227
1 Rule
The Oracle Linux operating system must ignore Internet Protocol version 4 (IPv4) 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.
SRG-OS-000480-GPOS-00227
1 Rule
The Oracle Linux operating system must not allow interfaces to perform Internet Protocol version 4 (IPv4) Internet Control Message Protocol (ICMP) redirects by default.
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.
SRG-OS-000480-GPOS-00227
1 Rule
The Oracle Linux operating system must not send Internet Protocol version 4 (IPv4) 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.
SRG-OS-000480-GPOS-00227
1 Rule
Network interfaces configured on The Oracle Linux operating system 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 authorized personnel only.
SRG-OS-000480-GPOS-00227
1 Rule
The Oracle Linux operating system 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
The Oracle Linux operating system must not have a File Transfer Protocol (FTP) server package installed unless needed.
High Severity
The FTP service provides an unencrypted remote access that does not provide for the confidentiality and integrity of user passwords 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 file transfer methods must be used in place of this service.
SRG-OS-000480-GPOS-00227
1 Rule
The Oracle Linux operating system must not have the Trivial File Transfer Protocol (TFTP) server package installed if not required for operational support.
High Severity
If TFTP is required for operational support (such as the transmission of router configurations) its use must be documented with the Information System Security Officer (ISSO), restricted to only authorized personnel, and have access control rules established.
SRG-OS-000480-GPOS-00227
1 Rule
The Oracle Linux operating system must be configured so that remote X connections are disabled, unless to fulfill documented and validated mission requirements.
Medium Severity
The security risk of using X11 forwarding is that the client's X11 display server may be exposed to attack when the SSH client requests forwarding. A system administrator may have a stance in which they want to protect clients that may expose themselves to attack by unwittingly requesting X11 forwarding, which can warrant a ''no'' setting. X11 forwarding should be enabled with caution. Users with the ability to bypass file permissions on the remote host (for the user's X11 authorization database) can access the local X11 display through the forwarded connection. An attacker may then be able to perform activities such as keystroke monitoring if the ForwardX11Trusted option is also enabled. If X11 services are not required for the system's intended function, they should be disabled or restricted as appropriate to the system’s needs.
SRG-OS-000480-GPOS-00227
1 Rule
The Oracle Linux operating system must be configured so that if the Trivial File Transfer Protocol (TFTP) server is required, the TFTP daemon is configured to operate in secure mode.
Medium Severity
Restricting TFTP to a specific directory prevents remote users from copying, transferring, or overwriting system files.
SRG-OS-000480-GPOS-00227
1 Rule
The Oracle Linux operating system must not have a graphical display manager installed unless approved.
Medium Severity
Internet services not required for system or application processes must not be active 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
The Oracle Linux operating system must not be performing 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 software is used when not required, system network information may be unnecessarily transmitted across the network.
SRG-OS-000480-GPOS-00227
1 Rule
The Oracle Linux operating system must be configured so that the Network File System (NFS) is configured to use RPCSEC_GSS.
Medium Severity
When an NFS server is configured to use RPCSEC_SYS, a selected userid and groupid are used to handle requests from the remote user. The userid and groupid could mistakenly or maliciously be set incorrectly. The RPCSEC_GSS method of authentication uses certificates on the server and client systems to more securely authenticate the remote mount request.
SRG-OS-000480-GPOS-00227
1 Rule
SNMP community strings on the Oracle Linux operating system must be changed from the default.
High Severity
Whether active or not, default Simple Network Management Protocol (SNMP) community strings must be changed to maintain security. If the service is running with the default authenticators, anyone can gather data about the system and the network and use the information to potentially compromise the integrity of the system or network(s). It is highly recommended that SNMP version 3 user authentication and message encryption be used in place of the version 2 community strings.
SRG-OS-000480-GPOS-00227
1 Rule
The Oracle Linux operating system access control program must be configured to grant or deny system access to specific hosts and services.
Medium Severity
If the systems access control program is not configured with appropriate rules for allowing and denying access to system network resources, services may be accessible to unauthorized hosts.
SRG-OS-000480-GPOS-00227
1 Rule
The Oracle Linux operating system 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
The Oracle Linux operating system must not forward IPv6 source-routed packets.
Medium Severity
Source-routed packets allow the source of the packet to suggest that 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 IPv6 forwarding is enabled and the system is functioning as a router.
SRG-OS-000105-GPOS-00052
1 Rule
The Oracle Linux operating system must have the required packages for multifactor authentication 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, non-organization-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). Satisfies: SRG-OS-000375-GPOS-00160, SRG-OS-000375-GPOS-00161, SRG-OS-000377-GPOS-00162
SRG-OS-000375-GPOS-00160
1 Rule
The Oracle Linux operating system must implement multifactor authentication for access to privileged accounts via pluggable authentication modules (PAM).
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, non-organization-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). Satisfies: SRG-OS-000375-GPOS-00160, SRG-OS-000375-GPOS-00161, SRG-OS-000377-GPOS-00162
SRG-OS-000375-GPOS-00160
1 Rule
The Oracle Linux operating system must implement certificate status checking for PKI 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, non-organization-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). Satisfies: SRG-OS-000375-GPOS-00160, SRG-OS-000375-GPOS-00161, SRG-OS-000377-GPOS-00162
SRG-OS-000424-GPOS-00188
1 Rule
The Oracle Linux operating system must be configured so that all wireless network adapters are disabled.
Medium Severity
The use of wireless networking can introduce many different attack vectors into the organization's network. Common attack vectors such as malicious association and ad hoc networks will allow an attacker to spoof a wireless access point (AP), allowing validated systems to connect to the malicious AP, and enabling the attacker to monitor and record network traffic. These malicious APs can also serve to create a man-in-the-middle attack, or be used to create a denial of service to valid network resources.
SRG-OS-000057-GPOS-00027
1 Rule
The Oracle Linux operating system must protect audit information from unauthorized read, modification, or deletion.
Medium Severity
If audit information were to become compromised, then forensic analysis and discovery of the true source of potentially malicious system activity is impossible to achieve. To ensure the veracity of audit information, the operating system must protect audit information from unauthorized modification. Audit information includes all information (e.g., audit records, audit settings, audit reports) needed to successfully audit information system activity. Satisfies: SRG-OS-000057-GPOS-00027, SRG-OS-000058-GPOS-00028, SRG-OS-000059-GPOS-00029, SRG-OS-000206-GPOS-00084
SRG-OS-000480-GPOS-00227
1 Rule
The Oracle Linux operating system must be configured so the x86 Ctrl-Alt-Delete key sequence is disabled in the Graphical User Interface.
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 the graphical 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-000480-GPOS-00227
1 Rule
The Oracle Linux operating system must be configured so that all world-writable directories are 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-000114-GPOS-00059
1 Rule
The Oracle Linux operating system must disable the graphical user interface automounter unless required.
Medium Severity
Automatically mounting file systems permits easy introduction of unknown devices, thereby facilitating malicious activity. Satisfies: SRG-OS-000114-GPOS-00059, SRG-OS-000378-GPOS-00163, SRG-OS-000480-GPOS-00227
SRG-OS-000373-GPOS-00156
1 Rule
The Oracle Linux operating system must be configured so users must re-authenticate 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 reauthenticate. Satisfies: SRG-OS-000373-GPOS-00156, SRG-OS-000373-GPOS-00157, SRG-OS-000373-GPOS-00158
SRG-OS-000445-GPOS-00199
1 Rule
The Oracle Linux operating system must enable the SELinux targeted policy.
Medium Severity
Without verification of the security functions, security functions may not operate correctly and the failure may go unnoticed. Security functions are 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.
SRG-OS-000480-GPOS-00227
1 Rule
The Oracle Linux operating system 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 DIPSLAY environment variable to localhost. This prevents remote hosts from connecting to the proxy display.
SRG-OS-000480-GPOS-00227
1 Rule
The Oracle Linux operating system must restrict privilege elevation to authorized personnel.
Medium Severity
The sudo command allows a user to execute programs with elevated (administrator) privileges. It prompts the user for their password and confirms your request to execute a command by checking a file, called sudoers. 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
The Oracle Linux operating system must use the invoking user's password for privilege escalation when using "sudo".
Medium Severity
The sudoers security policy requires that users authenticate themselves before they can use sudo. When sudoers requires authentication, it validates the invoking user's credentials. 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. For more information on each of the listed configurations, reference the sudoers(5) manual page.
SRG-OS-000373-GPOS-00156
1 Rule
The Oracle Linux operating system must require re-authentication 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 organization requires the user to re-authenticate when using the "sudo" command. If the value is set to an integer less than 0, the user's time stamp will not expire and the user will not have to re-authenticate for privileged actions until the user's session is terminated.
SRG-OS-000080-GPOS-00048
1 Rule
Oracle Linux operating systems version 7.2 or newer booted with a BIOS must have a unique name for the grub superusers account when booting into single-user and maintenance modes.
Medium Severity
If the system does not require valid authentication before it boots into single-user or maintenance mode, anyone who invokes single-user or maintenance mode is granted privileged access to all files on the system. GRUB 2 is the default boot loader for Oracle Linux 7 and is designed to require a password to boot into single-user mode or make modifications to the boot menu. The GRUB 2 superuser account is an account of last resort. Establishing a unique username for this account hardens the boot loader against brute force attacks. Due to the nature of the superuser account database being distinct from the OS account database, this allows the use of a username that is not among those within the OS account database. Examples of non-unique superusers names are root, superuser, unlock, etc.
SRG-OS-000080-GPOS-00048
1 Rule
Oracle Linux operating systems version 7.2 or newer booted with United Extensible Firmware Interface (UEFI) must have a unique name for the grub superusers account when booting into single-user mode and maintenance.
Medium Severity
If the system does not require valid authentication before it boots into single-user or maintenance mode, anyone who invokes single-user or maintenance mode is granted privileged access to all files on the system. GRUB 2 is the default boot loader for Oracle Linux 7 and is designed to require a password to boot into single-user mode or make modifications to the boot menu. The GRUB 2 superuser account is an account of last resort. Establishing a unique username for this account hardens the boot loader against brute force attacks. Due to the nature of the superuser account database being distinct from the OS account database, this allows the use of a username that is not among those within the OS account database. Examples of non-unique superusers names are root, superuser, unlock, etc.
SRG-OS-000324-GPOS-00125
1 Rule
The Oracle Linux operating system must confine SELinux users to roles that conform to least privilege.
Medium Severity
Preventing nonprivileged users from executing privileged functions mitigates the risk that unauthorized individuals or processes may gain unnecessary access to information or privileges. Privileged functions include, for example, establishing accounts, performing system integrity checks, or administering cryptographic key management activities. Nonprivileged users are individuals who do not possess appropriate authorizations. Circumventing intrusion detection and prevention mechanisms or malicious code protection mechanisms are examples of privileged functions that require protection from nonprivileged users.
SRG-OS-000324-GPOS-00125
1 Rule
The Oracle Linux operating system must not allow privileged accounts to utilize SSH.
Medium Severity
Preventing non-privileged users from executing privileged functions mitigates the risk that unauthorized individuals or processes may gain unnecessary access to information or privileges. Privileged functions include, for example, establishing accounts, performing system integrity checks, or administering cryptographic key management activities. Non-privileged users are individuals who do not possess appropriate authorizations. Circumventing intrusion detection and prevention mechanisms or malicious code protection mechanisms are examples of privileged functions that require protection from non-privileged users.
SRG-OS-000324-GPOS-00125
1 Rule
The Oracle Linux operating system must elevate the SELinux context when an administrator calls the sudo command.
Medium Severity
Preventing nonprivileged users from executing privileged functions mitigates the risk that unauthorized individuals or processes may gain unnecessary access to information or privileges. Privileged functions include, for example, establishing accounts, performing system integrity checks, or administering cryptographic key management activities. Nonprivileged users are individuals who do not possess appropriate authorizations. Circumventing intrusion detection and prevention mechanisms or malicious code protection mechanisms are examples of privileged functions that require protection from nonprivileged users.
SRG-OS-000480-GPOS-00227
1 Rule
The Oracle Linux operating system must not have accounts configured with blank or null passwords.
High 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 must never be used in operational environments.
SRG-OS-000480-GPOS-00227
1 Rule
The Oracle Linux operating system must specify the default "include" directory for the /etc/sudoers file.
Medium Severity
The "sudo" command allows authorized users to run programs (including shells) as other users, system users, and root. The "/etc/sudoers" file is used to configure authorized "sudo" users as well as the programs they are allowed to run. Some configuration options in the "/etc/sudoers" file allow configured users to run programs without re-authenticating. Use of these configuration options makes it easier for one compromised account to be used to compromise other accounts. It is possible to include other sudoers files from within the sudoers file currently being parsed using the #include and #includedir directives. When sudo reaches this line it will suspend processing of the current file (/etc/sudoers) and switch to the specified file/directory. Once the end of the included file(s) is reached, the rest of /etc/sudoers will be processed. Files that are included may themselves include other files. A hard limit of 128 nested include files is enforced to prevent include file loops.
SRG-OS-000373-GPOS-00156
1 Rule
The Oracle Linux operating system 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. Satisfies: SRG-OS-000373-GPOS-00156, SRG-OS-000373-GPOS-00157, SRG-OS-000373-GPOS-00158
SRG-OS-000445-GPOS-00199
1 Rule
The Oracle Linux operating system must use a file integrity tool to verify correct operation of all security functions.
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 the Oracle Linux operating system performing security function verification/testing and/or systems and environments that require this functionality.
SRG-OS-000123-GPOS-00064
1 Rule
The Oracle Linux operating system must automatically expire temporary accounts within 72 hours.
Medium Severity
Temporary accounts are privileged or nonprivileged accounts that are established during pressing circumstances, such as new software or hardware configuration or an incident response, where the need for prompt account activation requires bypassing normal account authorization procedures. If any inactive temporary accounts are left enabled on the system and are not either manually removed or automatically expired within 72 hours, the security posture of the system will be degraded and exposed to exploitation by unauthorized users or insider threat actors. Temporary accounts are different from emergency accounts. Emergency accounts, also known as "last resort" or "break glass" accounts, are local logon accounts enabled on the system for emergency use by authorized system administrators to manage a system when standard logon methods are failing or not available. Emergency accounts are not subject to manual removal or scheduled expiration requirements. The automatic expiration of temporary accounts may be extended as needed by the circumstances but it must not be extended indefinitely. A documented permanent account should be established for privileged users who need long-term maintenance accounts.
SRG-OS-000033-GPOS-00014
1 Rule
The Oracle Linux operating system SSH server must be configured to use only FIPS-validated key exchange algorithms.
Medium Severity
The use of FIPS-validated cryptographic algorithms is enforced by enabling kernel FIPS mode. In the event that kernel FIPS mode is disabled, the use of nonvalidated cryptographic algorithms will be permitted systemwide. The SSH server configuration must manually define only FIPS-validated key exchange algorithms to prevent the use of nonvalidated algorithms.
SRG-OS-000029-GPOS-00010
1 Rule
The Oracle Linux operating system must have the screen package installed.
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 log out 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, operating systems need to be able to identify when a user's session has idled and take action to initiate the session lock. The screen and tmux packages allow for a session lock to be implemented and configured.
SRG-OS-000138-GPOS-00069
1 Rule
The Oracle Linux operating system must restrict access to the kernel message buffer.
Low Severity
Restricting access to the kernel message buffer limits access only to root. This prevents attackers from gaining additional system information as a nonprivileged user.
SRG-OS-000073-GPOS-00041
1 Rule
The Oracle Linux operating system must be configured to prevent overwriting of custom authentication configuration settings by the authconfig utility.
Medium Severity
When using the authconfig utility to modify authentication configuration settings, the "system-auth" and "password-auth" files and any custom settings that they may contain are overwritten. This can be avoided by creating new local configuration files and creating new or moving existing symbolic links to them. The authconfig utility will recognize the local configuration files and not overwrite them, while writing its own settings to the original configuration files.
SRG-OS-000366-GPOS-00153
1 Rule
The Oracle Linux operating system must ensure cryptographic verification of vendor software packages.
Medium Severity
Cryptographic verification of vendor software packages ensures that all software packages are obtained from a valid source and protects against spoofing that could lead to installation of malware on the system. Oracle cryptographically signs all software packages, which includes updates, with a GPG key to verify that they are valid.
SRG-OS-000480-GPOS-00227
1 Rule
The Oracle Linux operating system must disable the login screen user list for graphical user interfaces.
Medium Severity
Leaving the user list enabled is a security risk as it allows anyone with physical access to the system to enumerate known user accounts without authenticated access to the system.
SRG-OS-000363-GPOS-00150
1 Rule
The Oracle Linux operating system must be configured to allow sending email notifications of unauthorized configuration changes to designated personnel.
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 IMO/ISSO and SAs must be notified via email and/or monitoring system trap when there is an unauthorized modification of a configuration item.
SRG-OS-000256-GPOS-00097
1 Rule
The Oracle Linux operating system must be configured so that the file permissions, ownership, and group membership of system files and commands match the vendor values.
High Severity
Discretionary access control is weakened if a user or group has access permissions to system files and directories greater than the default. Satisfies: SRG-OS-000257-GPOS-00098, SRG-OS-000278-GPOS-00108