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XCCDF
SUSE Linux Enterprise Micro (SLEM) 5 Security Technical Implementation Guide
Profiles
III - Administrative Classified
III - Administrative Classified
An XCCDF Profile
Details
Items
Prose
211 rules organized in 211 groups
SRG-OS-000191-GPOS-00080
1 Rule
SLEM 5 must implement an endpoint security tool.
Medium Severity
Adding endpoint security tools can provide the capability to automatically take actions in response to malicious behavior, which can provide additional agility in reacting to network threats. These tools also often include a reporting capability to provide network awareness of the system, which may not otherwise exist in an organization's systems management regime.
SRG-OS-000023-GPOS-00006
1 Rule
SLEM 5 must display the Standard Mandatory DOD Notice and Consent Banner before granting any local or remote connection to the system.
Medium Severity
Display of a standardized and approved use notification before granting access to SLEM 5 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 SLEM 5 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."
SRG-OS-000480-GPOS-00227
1 Rule
SLEM 5 must disable the x86 Ctrl-Alt-Delete key sequence.
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 user interface 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-000080-GPOS-00048
1 Rule
SLEM 5 with a basic input/output system (BIOS) must require authentication upon booting into single-user and maintenance modes.
High Severity
To mitigate the risk of unauthorized access to sensitive information by entities that have been issued certificates by DOD-approved PKIs, all DOD systems (e.g., web servers and web portals) must be properly configured to incorporate access control methods that do not rely solely on the possession of a certificate for access. Successful authentication must not automatically give an entity access to an asset or security boundary. Authorization procedures and controls must be implemented to ensure each authenticated entity also has a validated and current authorization. Authorization is the process of determining whether an entity, once authenticated, is permitted to access a specific asset. Information systems use access control policies and enforcement mechanisms to implement this requirement. Access control policies include identity-based policies, role-based policies, and attribute-based policies. Access enforcement mechanisms include access control lists, access control matrices, and cryptography. These policies and mechanisms must be employed by the application to control access between users (or processes acting on behalf of users) and objects (e.g., devices, files, records, processes, programs, and domains) in the information system.
SRG-OS-000080-GPOS-00048
1 Rule
SLEM 5 with Unified Extensible Firmware Interface (UEFI) implemented must require authentication upon booting into single-user mode and maintenance.
High Severity
If the system allows a user to boot into single-user or maintenance mode without authentication, any user that invokes single-user or maintenance mode is granted privileged access to all system information.
SRG-OS-000138-GPOS-00069
1 Rule
SLEM 5 must restrict access to the kernel message buffer.
Medium 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-000480-GPOS-00227
1 Rule
SLEM 5 kernel core dumps must be disabled 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 (DoS) by exhausting the available space on the target file system partition.
SRG-OS-000433-GPOS-00193
1 Rule
Address space layout randomization (ASLR) must be implemented by SLEM 5 to protect memory from unauthorized code execution.
Medium Severity
Some adversaries launch attacks with the intent of executing code in nonexecutable regions of memory or in memory locations that are prohibited. Security safeguards employed to protect memory include, for example, data execution prevention and address space layout randomization. Data execution prevention safeguards can either be hardware enforced or software enforced, with hardware providing the greater strength of mechanism. Examples of attacks are buffer overflow attacks.
SRG-OS-000433-GPOS-00192
1 Rule
SLEM 5 must implement kptr-restrict to prevent the leaking of internal kernel addresses.
Medium Severity
Some adversaries launch attacks with the intent of executing code in nonexecutable regions of memory or in memory locations that are prohibited. Security safeguards employed to protect memory include, for example, data execution prevention and address space layout randomization. Data execution prevention safeguards can either be hardware enforced or software enforced, with hardware providing the greater strength of mechanism. Examples of attacks are buffer overflow attacks.
SRG-OS-000480-GPOS-00227
1 Rule
Vendor-packaged SLEM 5 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 SLEM 5 and application software patched is a common mistake made by IT professionals. New patches are released frequently, and it is often difficult for even experienced system administrators (SAs) to keep up with of all the new patches. When new weaknesses in a SLEM 5 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-000366-GPOS-00153
1 Rule
The SLEM 5 tool zypper must have gpgcheck enabled.
High Severity
Changes to any software components can have significant effects on the overall security of SLEM 5. This requirement ensures the software has not been tampered with and has been provided by a trusted vendor. Accordingly, patches, service packs, device drivers, or SLEM 5 components must be signed with a certificate recognized and approved by the organization. Verifying the authenticity of the software prior to installation validates the integrity of the patch or upgrade received from a vendor. This ensures the software has not been tampered with and that it has been provided by a trusted vendor. Self-signed certificates are disallowed by this requirement. SLEM 5 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 Certification Authority (CA).
SRG-OS-000437-GPOS-00194
1 Rule
SLEM 5 must remove all outdated software components after updated versions have been installed.
Medium Severity
Previous versions of software components that are not removed from the information system after updates have been installed may be exploited by adversaries. Some information technology products may remove older versions of software automatically from the information system.
SRG-OS-000028-GPOS-00009
1 Rule
SLEM 5 must use vlock to allow for session locking.
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.
SRG-OS-000074-GPOS-00042
1 Rule
SLEM 5 must not have the telnet-server package installed.
High Severity
It is detrimental for SLEM 5 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. SLEM 5 is 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 and functions). Examples of nonessential 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-000480-GPOS-00227
1 Rule
A separate file system must be used for SLEM 5 user home directories (such as /home or an equivalent).
Medium 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
SLEM 5 must use a separate file system for /var.
Medium 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
SLEM 5 must use a separate file system for the system audit data path.
Medium 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
SLEM 5 file systems that are being imported via Network File System (NFS) must be mounted to prevent files with the setuid and setgid bit set from being executed.
Medium Severity
The "nosuid" mount option causes the system to not execute "setuid" and "setgid" files with owner privileges. This option must be used for mounting any file system not containing approved "setuid" and "setguid" files. Executing files from untrusted file systems increases the opportunity for unprivileged users to attain unauthorized administrative access.
SRG-OS-000480-GPOS-00227
1 Rule
SLEM 5 file systems that are being imported via Network File System (NFS) must be mounted to prevent binary files from being executed.
Medium Severity
The "noexec" mount option causes the system to not execute binary files. This option must be used for mounting any file system not containing approved binary files, as they may be incompatible. Executing files from untrusted file systems increases the opportunity for unprivileged users to attain unauthorized administrative access.
SRG-OS-000480-GPOS-00227
1 Rule
SLEM 5 file systems that are used with removable media must be mounted to prevent files with the setuid and setgid bit set from being executed.
Medium Severity
The "nosuid" mount option causes the system to not execute "setuid" and "setgid" files with owner privileges. This option must be used for mounting any file system not containing approved "setuid" and "setguid" files. Executing files from untrusted file systems increases the opportunity for unprivileged users to attain unauthorized administrative access.
SRG-OS-000185-GPOS-00079
1 Rule
All SLEM 5 persistent disk partitions must implement cryptographic mechanisms to prevent unauthorized disclosure or modification of all information that requires at-rest protection.
High Severity
SLEM 5 handling data requiring data-at-rest protections must employ cryptographic mechanisms to prevent unauthorized disclosure and modification of the information at rest. Selection of a cryptographic mechanism is based on the need to protect the integrity of organizational information. The strength of the mechanism is commensurate with the security category and/or classification of the information. Organizations have the flexibility to either encrypt all information on storage devices (i.e., full disk encryption) or encrypt specific data structures (e.g., files, records, or fields).
SRG-OS-000480-GPOS-00227
1 Rule
SLEM 5 file systems that contain user home directories must be mounted to prevent files with the setuid and setgid bit set from being executed.
Medium Severity
The "nosuid" mount option causes the system to not execute setuid and setgid files with owner privileges. This option must be used for mounting any file system not containing approved setuid and setguid files. Executing files from untrusted file systems increases the opportunity for unprivileged users to attain unauthorized administrative access.
SRG-OS-000114-GPOS-00059
1 Rule
SLEM 5 must disable the file system automounter unless required.
Medium Severity
Automatically mounting file systems permits easy introduction of unknown devices, thereby facilitating malicious activity.
SRG-OS-000259-GPOS-00100
1 Rule
SLEM 5 must have directories that contain system commands set to a mode of 755 or less permissive.
Medium Severity
If SLEM 5 were to allow any user to make changes to software libraries, then those changes might be implemented without undergoing the appropriate testing and approvals that are part of a robust change management process. This requirement applies to SLEM 5 with software libraries that are accessible and configurable, as in the case of interpreted languages. Software libraries also include privileged programs which execute with escalated privileges. Only qualified and authorized individuals must be allowed to obtain access to information system components for purposes of initiating changes, including upgrades and modifications.
SRG-OS-000259-GPOS-00100
1 Rule
SLEM 5 must have system commands set to a mode of 755 or less permissive.
Medium Severity
If SLEM 5 were to allow any user to make changes to software libraries, then those changes might be implemented without undergoing the appropriate testing and approvals that are part of a robust change management process. This requirement applies to SLEM 5 with software libraries that are accessible and configurable, as in the case of interpreted languages. Software libraries also include privileged programs which execute with escalated privileges. Only qualified and authorized individuals must be allowed to obtain access to information system components for purposes of initiating changes, including upgrades and modifications.
SRG-OS-000259-GPOS-00100
1 Rule
SLEM 5 library directories must have mode 755 or less permissive.
Medium Severity
If SLEM 5 were to allow any user to make changes to software libraries, then those changes might be implemented without undergoing the appropriate testing and approvals that are part of a robust change management process. This requirement applies to SLEM 5 with software libraries that are accessible and configurable, as in the case of interpreted languages. Software libraries also include privileged programs which execute with escalated privileges. Only qualified and authorized individuals must be allowed to obtain access to information system components for purposes of initiating changes, including upgrades and modifications.
SRG-OS-000259-GPOS-00100
1 Rule
SLEM 5 library files must have mode 755 or less permissive.
Medium Severity
If SLEM 5 were to allow any user to make changes to software libraries, then those changes might be implemented without undergoing the appropriate testing and approvals that are part of a robust change management process. This requirement applies to SLEM 5 with software libraries that are accessible and configurable, as in the case of interpreted languages. Software libraries also include privileged programs which execute with escalated privileges. Only qualified and authorized individuals must be allowed to obtain access to information system components for purposes of initiating changes, including upgrades and modifications.
SRG-OS-000480-GPOS-00227
1 Rule
All SLEM 5 local interactive user home directories must have mode 750 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
All SLEM 5 local initialization files must have mode 740 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
SLEM 5 SSH daemon public host key files must have mode 644 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
SLEM 5 SSH daemon private host key files must have mode 640 or less permissive.
Medium Severity
If an unauthorized user obtains the private SSH host key file, the host could be impersonated.
SRG-OS-000259-GPOS-00100
1 Rule
SLEM 5 library files must be owned by root.
Medium Severity
If SLEM 5 were to allow any user to make changes to software libraries, then those changes might be implemented without undergoing the appropriate testing and approvals that are part of a robust change management process. This requirement applies to SLEM 5 with software libraries that are accessible and configurable, as in the case of interpreted languages. Software libraries also include privileged programs which execute with escalated privileges. Only qualified and authorized individuals must be allowed to obtain access to information system components for purposes of initiating changes, including upgrades and modifications.
SRG-OS-000259-GPOS-00100
1 Rule
SLEM 5 library files must be group-owned by root.
Medium Severity
If SLEM 5 were to allow any user to make changes to software libraries, then those changes might be implemented without undergoing the appropriate testing and approvals that are part of a robust change management process. This requirement applies to SLEM 5 with software libraries that are accessible and configurable, as in the case of interpreted languages. Software libraries also include privileged programs which execute with escalated privileges. Only qualified and authorized individuals must be allowed to obtain access to information system components for purposes of initiating changes, including upgrades and modifications.
SRG-OS-000259-GPOS-00100
1 Rule
SLEM 5 library directories must be owned by root.
Medium Severity
If SLEM 5 were to allow any user to make changes to software libraries, then those changes might be implemented without undergoing the appropriate testing and approvals that are part of a robust change management process. This requirement applies to SLEM 5 with software libraries that are accessible and configurable, as in the case of interpreted languages. Software libraries also include privileged programs which execute with escalated privileges. Only qualified and authorized individuals must be allowed to obtain access to information system components for purposes of initiating changes, including upgrades and modifications.
SRG-OS-000259-GPOS-00100
1 Rule
SLEM 5 library directories must be group-owned by root.
Medium Severity
If SLEM 5 were to allow any user to make changes to software libraries, then those changes might be implemented without undergoing the appropriate testing and approvals that are part of a robust change management process. This requirement applies to SLEM 5 with software libraries that are accessible and configurable, as in the case of interpreted languages. Software libraries also include privileged programs which execute with escalated privileges. Only qualified and authorized individuals must be allowed to obtain access to information system components for purposes of initiating changes, including upgrades and modifications.
SRG-OS-000259-GPOS-00100
1 Rule
SLEM 5 must have system commands owned by root.
Medium Severity
If SLEM 5 were to allow any user to make changes to software libraries, then those changes might be implemented without undergoing the appropriate testing and approvals that are part of a robust change management process. This requirement applies to SLEM 5 with software libraries that are accessible and configurable, as in the case of interpreted languages. Software libraries also include privileged programs which execute with escalated privileges. Only qualified and authorized individuals must be allowed to obtain access to information system components for purposes of initiating changes, including upgrades and modifications.
SRG-OS-000259-GPOS-00100
1 Rule
SLEM 5 must have system commands group-owned by root or a system account.
Medium Severity
If SLEM 5 were to allow any user to make changes to software libraries, then those changes might be implemented without undergoing the appropriate testing and approvals that are part of a robust change management process. This requirement applies to SLEM 5 with software libraries that are accessible and configurable, as in the case of interpreted languages. Software libraries also include privileged programs which execute with escalated privileges. Only qualified and authorized individuals must be allowed to obtain access to information system components for purposes of initiating changes, including upgrades and modifications.
SRG-OS-000259-GPOS-00100
1 Rule
SLEM 5 must have directories that contain system commands owned by root.
Medium Severity
If SLEM 5 were to allow any user to make changes to software libraries, then those changes might be implemented without undergoing the appropriate testing and approvals that are part of a robust change management process. This requirement applies to SLEM 5 with software libraries that are accessible and configurable, as in the case of interpreted languages. Software libraries also include privileged programs which execute with escalated privileges. Only qualified and authorized individuals must be allowed to obtain access to information system components for purposes of initiating changes, including upgrades and modifications.
SRG-OS-000259-GPOS-00100
1 Rule
SLEM 5 must have directories that contain system commands group-owned by root.
Medium Severity
If SLEM 5 were to allow any user to make changes to software libraries, then those changes might be implemented without undergoing the appropriate testing and approvals that are part of a robust change management process. This requirement applies to SLEM 5 with software libraries that are accessible and configurable, as in the case of interpreted languages. Software libraries also include privileged programs which execute with escalated privileges. Only qualified and authorized individuals must be allowed to obtain access to information system components for purposes of initiating changes, including upgrades and modifications.
SRG-OS-000480-GPOS-00227
1 Rule
All SLEM 5 files and directories must have a valid owner.
Medium Severity
Unowned files and directories may be unintentionally inherited if a user is assigned the same User Identifier (UID) as the UID of the unowned files.
SRG-OS-000480-GPOS-00227
1 Rule
All SLEM 5 files and directories must have a valid group owner.
Medium Severity
Files without a valid group owner may be unintentionally inherited if a group is assigned the same Group Identifier (GID) as the GID of the files without a valid group owner.
SRG-OS-000480-GPOS-00227
1 Rule
All SLEM 5 local interactive user home directories must be group-owned by the home directory owner's primary group.
Medium Severity
If the Group Identifier (GID) of a local interactive 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
All SLEM 5 world-writable directories must be group-owned by root, sys, bin, or an application group.
Medium Severity
If a world-writable directory has the sticky bit set and is not group-owned by a privileged 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-000138-GPOS-00069
1 Rule
The sticky bit must be set on all SLEM 5 world-writable directories.
Medium Severity
Preventing unauthorized information transfers mitigates the risk of information, including encrypted representations of information, produced by the actions of prior users/roles (or the actions of processes acting on behalf of prior users/roles) from being available to any current users/roles (or current processes) that obtain access to shared system resources (e.g., registers, main memory, and hard disks) after those resources have been released back to information systems. The control of information in shared resources is also commonly referred to as object reuse and residual information protection. This requirement generally applies to the design of an information technology product, but it can also apply to the configuration of particular information system components that are, or use, such products. This can be verified by acceptance/validation processes in DOD or other government agencies. There may be shared resources with configurable protections (e.g., files in storage) that may be assessed on specific information system components.
SRG-OS-000206-GPOS-00084
1 Rule
SLEM 5 must prevent unauthorized users from accessing system error messages.
Medium Severity
Only authorized personnel should be aware of errors and the details of the errors. Error messages are an indicator of an organization's operational state or can identify SLEM 5 or platform. Additionally, Personally Identifiable Information (PII) and operational information must not be revealed through error messages to unauthorized personnel or their designated representatives. The structure and content of error messages must be carefully considered by the organization and development team. The extent to which the information system is able to identify and handle error conditions is guided by organizational policy and operational requirements.
SRG-OS-000205-GPOS-00083
1 Rule
SLEM 5 must generate error messages that provide information necessary for corrective actions without revealing information that could be exploited by adversaries.
Medium Severity
Any operating system providing too much information in error messages risks compromising the data and security of the structure, and content of error messages needs to be carefully considered by the organization. Organizations carefully consider the structure/content of error messages. The extent to which information systems are able to identify and handle error conditions is guided by organizational policy and operational requirements. Information that could be exploited by adversaries includes, for example, erroneous logon attempts with passwords entered by mistake as the username, mission/business information that can be derived from (if not stated explicitly by) information recorded, and personal information, such as account numbers, social security numbers, and credit card numbers. The /var/log/btmp, /var/log/wtmp, and /var/log/lastlog files have group write and global read permissions to allow for the lastlog function to perform. Limiting the permissions beyond this configuration will result in the failure of functions that rely on the lastlog database.
SRG-OS-000096-GPOS-00050
1 Rule
SLEM 5 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 (PPSM) Category Assignments List (CAL) and vulnerability assessments.
Medium Severity
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. Additionally, operating system remote access functionality must have the capability to immediately disconnect current users remotely accessing the information system and/or disable further remote access. The speed of disconnect or disablement varies based on the criticality of mission functions and the need to eliminate immediate or future remote access to organizational information systems.
SRG-OS-000355-GPOS-00143
1 Rule
SLEM 5 clock must, for networked systems, be synchronized to an authoritative DOD time source at least every 24 hours.
Medium Severity
Inaccurate time stamps make it more difficult to correlate events and can lead to an inaccurate analysis. Determining the correct time a particular event occurred on a system is critical when conducting forensic analysis and investigating system events. 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).
SRG-OS-000480-GPOS-00227
1 Rule
SLEM 5 must not have network interfaces in promiscuous mode unless approved and documented.
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 then to collect information such as logon IDs, passwords, and key exchanges between systems. If the system is being used to perform a network troubleshooting function, the use of these tools must be documented with the information system security officer (ISSO) and restricted to only authorized personnel.
SRG-OS-000480-GPOS-00227
1 Rule
SLEM 5 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/IPv6 forwarding is enabled and the system is functioning as a router.
SRG-OS-000480-GPOS-00227
1 Rule
SLEM 5 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
SLEM 5 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
SLEM 5 must not allow interfaces to accept Internet Protocol version 4 (IPv4) Internet Control Message Protocol (ICMP) redirect messages 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 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
SLEM 5 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
SLEM 5 must not allow interfaces to send Internet Protocol version 4 (IPv4) Internet Control Message Protocol (ICMP) redirect messages 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
SLEM 5 must not be performing Internet Protocol version 4 (IPv4) 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-000142-GPOS-00071
1 Rule
SLEM 5 must be configured to use TCP syncookies.
Medium Severity
Denial of service (DoS) is a condition in which a resource is not available for legitimate users. When this occurs, the organization either cannot accomplish its mission or must operate at degraded capacity. Managing excess capacity ensures that sufficient capacity is available to counter flooding attacks. Employing increased capacity and service redundancy may reduce the susceptibility to some DoS attacks. Managing excess capacity may include, for example, establishing selected usage priorities, quotas, or partitioning.
SRG-OS-000480-GPOS-00227
1 Rule
SLEM 5 must not forward Internet Protocol version 6 (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 IPv4 forwarding is enabled and the system is functioning as a router.
SRG-OS-000480-GPOS-00227
1 Rule
SLEM 5 must not forward Internet Protocol version 6 (IPv6) 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
SLEM 5 must prevent Internet Protocol version 6 (IPv6) 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
SLEM 5 must not allow interfaces to accept Internet Protocol version 6 (IPv6) Internet Control Message Protocol (ICMP) redirect messages 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 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
SLEM 5 must not be performing Internet Protocol version 6 (IPv6) 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
SLEM 5 must not be performing Internet Protocol version 6 (IPv6) packet forwarding by default 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-000423-GPOS-00187
1 Rule
SLEM 5 must have SSH installed to protect the confidentiality and integrity of transmitted information.
High Severity
Without protection of the transmitted information, confidentiality and integrity may be compromised because unprotected communications can be intercepted and either read or altered. This requirement applies to both internal and external networks and all types of information system components from which information can be transmitted (e.g., servers, mobile devices, notebook computers, printers, copiers, scanners, and facsimile machines). Communication paths outside the physical protection of a controlled boundary are exposed to the possibility of interception and modification. Protecting the confidentiality and integrity of organizational information can be accomplished by physical means (e.g., employing physical distribution systems) or by logical means (e.g., employing cryptographic techniques). If physical means of protection are employed, logical means (cryptography) do not have to be employed, and vice versa.
SRG-OS-000423-GPOS-00187
1 Rule
SLEM 5 must use SSH to protect the confidentiality and integrity of transmitted information.
High Severity
Without protection of the transmitted information, confidentiality and integrity may be compromised because unprotected communications can be intercepted and either read or altered. This requirement applies to both internal and external networks and all types of information system components from which information can be transmitted (e.g., servers, mobile devices, notebook computers, printers, copiers, scanners, and facsimile machines). Communication paths outside the physical protection of a controlled boundary are exposed to the possibility of interception and modification. Protecting the confidentiality and integrity of organizational information can be accomplished by physical means (e.g., employing physical distribution systems) or by logical means (e.g., employing cryptographic techniques). If physical means of protection are employed, logical means (cryptography) do not have to be employed, and vice versa.
SRG-OS-000023-GPOS-00006
1 Rule
SLEM 5 must display the Standard Mandatory DOD Notice and Consent Banner before granting access via SSH.
Medium Severity
Display of a standardized and approved use notification before granting access to SLEM 5 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 SLEM 5 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."
SRG-OS-000480-GPOS-00229
1 Rule
SLEM 5 must not allow unattended or automatic logon via SSH.
High Severity
Failure to restrict system access via SSH to authenticated users negatively impacts SLEM 5 security.
SRG-OS-000163-GPOS-00072
1 Rule
SLEM 5 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.
SRG-OS-000126-GPOS-00066
1 Rule
SLEM 5 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 that the operating system terminates all sessions or network access; it only ends the unresponsive session and releases the resources associated with that session.
SRG-OS-000480-GPOS-00227
1 Rule
SLEM 5 SSH daemon must disable forwarded remote X connections for interactive users, 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-000033-GPOS-00014
1 Rule
SLEM 5 must implement DOD-approved encryption to protect the confidentiality of SSH remote connections.
High Severity
Without confidentiality protection mechanisms, unauthorized individuals may gain access to sensitive information via a remote access session. Remote access is access to DOD nonpublic information systems by an authorized user (or an information system) communicating through an external, nonorganization-controlled network. Remote access methods include, for example, dial-up, broadband, and wireless. Encryption provides a means to secure the remote connection to prevent unauthorized access to the data traversing the remote access connection (e.g., RDP), thereby providing a degree of confidentiality. The encryption strength of a mechanism is selected based on the security categorization of the information. The 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.
SRG-OS-000125-GPOS-00065
1 Rule
SLEM 5 SSH daemon must be configured to only use Message Authentication Codes (MACs) employing FIPS 140-2/140-3 approved cryptographic hash algorithms.
High Severity
Without cryptographic integrity protections, information can be altered by unauthorized users without detection. Remote access (e.g., RDP) is access to DOD nonpublic information systems by an authorized user (or an information system) communicating through an external, nonorganization-controlled network. Remote access methods include, for example, dial-up, broadband, and wireless. Cryptographic mechanisms used for protecting the integrity of information include, for example, signed hash functions using asymmetric cryptography enabling distribution of the public key to verify the hash information while maintaining the confidentiality of the secret key used to generate the hash. 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-000250-GPOS-00093
1 Rule
SLEM 5 SSH server must be configured to use only FIPS 140-2/140-3 validated key exchange algorithms.
High Severity
Without cryptographic integrity protections provided by FIPS 140-2/140-3 validated cryptographic algorithms, information can be viewed and altered by unauthorized users without detection. The system will attempt to use the first algorithm presented by the client that matches the server list. Listing the values "strongest to weakest" is a method to ensure the use of the strongest algorithm available to secure the SSH connection.
SRG-OS-000109-GPOS-00056
1 Rule
SLEM 5 must deny direct logons to the root account using remote access via SSH.
Medium Severity
To ensure individual accountability and prevent unauthorized access, organizational users must be individually identified and authenticated. A group authenticator is a generic account used by multiple individuals. Use of a group authenticator alone does not uniquely identify individual users. Examples of the group authenticator is the Unix OS "root" user account, the Windows "Administrator" account, the "sa" account, or a "helpdesk" account. For example, the Unix and Windows SLEM 5 offer a "switch user" capability, allowing users to authenticate with their individual credentials and, when needed, "switch" to the administrator role. This method provides for unique individual authentication prior to using a group authenticator. Users (and any processes acting on behalf of users) need to be uniquely identified and authenticated for all accesses other than those accesses explicitly identified and documented by the organization, which outlines specific user actions that can be performed on SLEM 5 without identification or authentication. Requiring individuals to be authenticated with an individual authenticator prior to using a group authenticator allows for traceability of actions, as well as adding an additional level of protection of the actions that can be taken with group account knowledge.
SRG-OS-000032-GPOS-00013
1 Rule
SLEM 5 must log SSH connection attempts and failures to the server.
Medium Severity
Remote access services, such as those providing remote access to network devices and information systems, which lack automated monitoring capabilities, increase risk and make remote user access management difficult at best. Remote access is access to DOD nonpublic information systems by an authorized user (or an information system) communicating through an external, nonorganization-controlled network. Remote access methods include, for example, dial-up, broadband, and wireless. Automated monitoring of remote access sessions allows organizations to detect cyberattacks and also ensure ongoing compliance with remote access policies by auditing connection activities of remote access capabilities, such as Remote Desktop Protocol (RDP), on a variety of information system components (e.g., servers, workstations, notebook computers, smartphones, and tablets).
SRG-OS-000480-GPOS-00227
1 Rule
SLEM 5 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
SLEM 5 SSH daemon must be configured to 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-000480-GPOS-00227
1 Rule
SLEM 5 SSH daemon must perform strict mode checking of home directory configuration files.
Medium Severity
If other users have access to modify user-specific SSH configuration files, they may be able to log on to the system as another user.
SRG-OS-000067-GPOS-00035
1 Rule
SLEM 5, for PKI-based authentication, must enforce authorized access to the corresponding private key.
Medium Severity
If the private key is discovered, an attacker can use the key to authenticate as an authorized user and gain access to the network infrastructure. The cornerstone of the PKI is the private key used to encrypt or digitally sign information. If the private key is stolen, this will lead to the compromise of the authentication and nonrepudiation gained through PKI because the attacker can use the private key to digitally sign documents and pretend to be the authorized user. Both the holders of a digital certificate and the issuing authority must protect the computers, storage devices, or whatever they use to keep the private keys.
SRG-OS-000480-GPOS-00227
1 Rule
There must be no .shosts files on SLEM 5.
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
There must be no shosts.equiv files on SLEM 5.
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-00229
1 Rule
SLEM 5 must not allow unattended or automatic logon via the graphical user interface (GUI).
High Severity
Failure to restrict system access to authenticated users negatively impacts SLEM 5 security.
SRG-OS-000299-GPOS-00117
1 Rule
SLEM 5 wireless network adapters must be disabled unless approved and documented.
Medium Severity
Without protection of communications with wireless peripherals, confidentiality and integrity may be compromised because unprotected communications can be intercepted and either read, altered, or used to compromise SLEM 5. This requirement applies to wireless peripheral technologies (e.g., wireless mice, keyboards, displays, etc.) used with a SLEM 5. Wireless peripherals (e.g., Wi-Fi/Bluetooth/IR keyboards, mice, pointing devices, and Near Field Communications [NFC]) present a unique challenge by creating an open, unsecured port on a computer. Wireless peripherals must meet DOD requirements for wireless data transmission and be approved for use by the AO. Even though some wireless peripherals, such as mice and pointing devices, do not ordinarily carry information that need to be protected, modification of communications with these wireless peripherals may be used to compromise SLEM 5. 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 communications with wireless peripherals can be accomplished by physical means (e.g., employing physical barriers to wireless radio frequencies) 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. If the wireless peripheral is only passing telemetry data, encryption of the data may not be required.
SRG-OS-000378-GPOS-00163
1 Rule
SLEM 5 must disable the USB mass storage kernel module.
Medium Severity
Without identifying devices, unidentified or unknown devices may be introduced, thereby facilitating malicious activity. Peripherals include but are not limited to such devices as flash drives, external storage, and printers.
SRG-OS-000480-GPOS-00227
1 Rule
All SLEM 5 local interactive user accounts, upon creation, must be 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 files they should own.
SRG-OS-000480-GPOS-00228
1 Rule
SLEM 5 default permissions must be defined in such a way that all authenticated users 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-00226
1 Rule
SLEM 5 shadow password suite must be configured to enforce a delay of at least five seconds between logon prompts following a failed logon attempt.
Medium Severity
Limiting the number of logon attempts over a certain time interval reduces the chances that an unauthorized user may gain access to an account.
SRG-OS-000480-GPOS-00227
1 Rule
All SLEM 5 local interactive users must have a home directory assigned in the /etc/passwd file.
Medium Severity
If local interactive users are not assigned a valid home directory, there is no place for the storage and control of files they should own.
SRG-OS-000480-GPOS-00227
1 Rule
All SLEM 5 local interactive user home directories defined in the /etc/passwd file must exist.
Medium Severity
If a local interactive user has a home directory defined that does not exist, the user may be given access to the / directory as the current working directory upon logon. This could create a denial of service (DoS) 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
All SLEM 5 local interactive user initialization files executable search paths must 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
All SLEM 5 local initialization files must not execute world-writable programs.
Medium Severity
If user start-up files execute world-writable programs, especially in unprotected directories, they could be maliciously modified to destroy user files or otherwise compromise the system at the user level. If the system is compromised at the user level, it is easier to elevate privileges to eventually compromise the system at the root and network level.
SRG-OS-000123-GPOS-00064
1 Rule
SLEM 5 must automatically expire temporary accounts within 72 hours.
Medium Severity
Temporary accounts are privileged or nonprivileged accounts 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-000123-GPOS-00064
1 Rule
SLEM 5 must never automatically remove or disable emergency administrator accounts.
Medium Severity
Emergency administrator 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.
SRG-OS-000480-GPOS-00227
1 Rule
SLEM 5 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-000480-GPOS-00227
1 Rule
SLEM 5 must not have unnecessary account capabilities.
Medium Severity
Accounts providing no operational purpose provide additional opportunities for system compromise. Therefore all necessary noninteractive accounts should not have an interactive shell assigned to them.
SRG-OS-000480-GPOS-00227
1 Rule
SLEM 5 root account must be the only account with 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 SLEM 5. Multiple accounts with a UID of "0" afford an opportunity for potential intruders to guess a password for a privileged account.
SRG-OS-000118-GPOS-00060
1 Rule
SLEM 5 must disable account identifiers (individuals, groups, roles, and devices) after 35 days of inactivity after password expiration.
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. SLEM 5 must track periods of inactivity and disable application identifiers after 35 days of inactivity.
SRG-OS-000104-GPOS-00051
1 Rule
SLEM 5 must not have duplicate User IDs (UIDs) for interactive users.
Medium Severity
To ensure accountability and prevent unauthenticated access, interactive users must be identified and authenticated to prevent potential misuse and compromise of the system. Interactive users include organizational employees or individuals the organization deems to have equivalent status of employees (e.g., contractors). Interactive users (and processes acting on behalf of users) must be uniquely identified and authenticated to all accesses, except for the following: 1) Accesses explicitly identified and documented by the organization. Organizations document specific user actions that can be performed on the information system without identification or authentication; and 2) Accesses that occur through authorized use of group authenticators without individual authentication. Organizations may require unique identification of individuals in group accounts (e.g., shared privilege accounts) or for detailed accountability of individual activity.
SRG-OS-000480-GPOS-00227
1 Rule
SLEM 5 must display the date and time of the last successful account logon upon logon.
Medium Severity
Providing users with feedback on when account accesses last occurred facilitates user recognition and reporting of unauthorized account use.
SRG-OS-000029-GPOS-00010
1 Rule
SLEM 5 must initiate a session lock after a 15-minute period of inactivity.
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 users to manually lock their SLEM 5 session prior to vacating the vicinity, SLEM 5 needs to 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-000021-GPOS-00005
1 Rule
SLEM 5 must lock an account after three consecutive invalid access attempts.
Medium Severity
By limiting the number of failed access 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. The pam_tally2.so module maintains a count of attempted accesses. This includes username entry into a logon field as well as password entry. With counting access attempts, it is possible to lock an account without presenting a password into the password field. This should be taken into consideration as it poses as an avenue for denial of service (DoS).
SRG-OS-000480-GPOS-00226
1 Rule
SLEM 5 must enforce a delay of at least five seconds between logon prompts following a failed logon attempt via pluggable authentication modules (PAM).
Medium Severity
Limiting the number of logon attempts over a certain time interval reduces the chances that an unauthorized user may gain access to an account.
SRG-OS-000021-GPOS-00005
1 Rule
SLEM 5 must use the default pam_tally2 tally directory.
Medium Severity
By limiting the number of failed logon attempts, the risk of unauthorized system access via user password guessing, otherwise known as brute-force attacks, is reduced. Limits are imposed by locking the account. SELinux, enforcing a targeted policy, will be required to match the default directory's security context type.
SRG-OS-000027-GPOS-00008
1 Rule
SLEM 5 must limit the number of concurrent sessions to 10 for all accounts and/or account types.
Low Severity
SLEM 5 management includes the ability to control the number of users and user sessions that use a SLEM 5. Limiting the number of allowed users and sessions per user is helpful in reducing the risks related to denial-of-service (DoS) attacks. This requirement addresses concurrent sessions for information system accounts and does not address concurrent sessions by single users via multiple system accounts. The maximum number of concurrent sessions should be defined based on mission needs and the operational environment for each system.
SRG-OS-000134-GPOS-00068
1 Rule
SLEM 5 must have policycoreutils package installed.
Low 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. Policycoreutils contains the policy core utilities that are required for basic operation of an SELinux-enabled system. These utilities include load_policy to load SELinux policies, setfile to label filesystems, newrole to switch roles, and run_init to run /etc/init.d scripts in the proper context.
SRG-OS-000134-GPOS-00068
1 Rule
SLEM 5 must use a Linux Security Module configured to enforce limits on system services.
High 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-000445-GPOS-00199
1 Rule
SLEM 5 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 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-000324-GPOS-00125
1 Rule
SLEM 5 must prevent nonprivileged users from executing privileged functions, including 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-000480-GPOS-00227
1 Rule
SLEM 5 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
SLEM 5 must reauthenticate users when changing authenticators, roles, or escalating privileges.
Medium Severity
Without reauthentication, users may access resources or perform tasks for which they do not have authorization. When SLEM 5 provides the capability to change user authenticators, change security roles, or escalate a functional capability, it is critical the user reauthenticate.
SRG-OS-000373-GPOS-00156
1 Rule
SLEM 5 must require reauthentication when using the "sudo" command.
Medium Severity
Without reauthentication, 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 reauthenticate 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 reauthenticate for privileged actions until the user's session is terminated.
SRG-OS-000480-GPOS-00227
1 Rule
SLEM 5 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 the 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
SLEM 5 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 reauthenticating. 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. For compatibility with sudo versions prior to 1.9.1, #include and #includedir are also accepted. 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-000069-GPOS-00037
1 Rule
SLEM 5 must enforce passwords that contain at least one uppercase character.
Medium Severity
Use of a complex password helps 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-000070-GPOS-00038
1 Rule
SLEM 5 must enforce passwords that contain at least one lowercase character.
Medium Severity
Use of a complex password helps 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-000071-GPOS-00039
1 Rule
SLEM 5 must enforce passwords that contain at least one numeric character.
Medium Severity
Use of a complex password helps increase the time and resources required to compromise the password. Password complexity, or strength, is a measure of the effectiveness of a password in resisting attempts at guessing and brute-force attacks. Password complexity is one factor of several that determines how long it takes to crack a password. The more complex the password, the greater the number of possible combinations that need to be tested before the password is compromised.
SRG-OS-000266-GPOS-00101
1 Rule
SLEM 5 must enforce passwords that contain at least one special character.
Medium Severity
Use of a complex password helps 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 in determining 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. Special characters are not alphanumeric. Examples include: ~ ! @ # $ % ^ *.
SRG-OS-000480-GPOS-00225
1 Rule
SLEM 5 must prevent the use of dictionary words for passwords.
Medium Severity
If SLEM 5 allows the user to select passwords based on dictionary words, this increases the chances of password compromise by increasing the opportunity for successful guesses and brute-force attacks.
SRG-OS-000078-GPOS-00046
1 Rule
SLEM 5 must employ passwords with a minimum of 15 characters.
Medium Severity
The shorter the password, the lower the number of possible combinations that need to be tested before the password is compromised. Password complexity, or strength, is a measure of the effectiveness of a password in resisting attempts at guessing and brute-force attacks. Password length is one factor of several that helps determine strength and how long it takes to crack a password. Use of more characters in a password helps exponentially increase the time and/or resources required to compromise the password.
SRG-OS-000072-GPOS-00040
1 Rule
SLEM 5 must require the change of at least eight of the total number of characters when passwords are changed.
Medium Severity
If SLEM 5 allows the user to consecutively reuse extensive portions of passwords, this increases the chances of password compromise by increasing the window of opportunity for attempts at guessing and brute-force attacks.
SRG-OS-000077-GPOS-00045
1 Rule
SLEM 5 must not allow passwords to be reused for a minimum of five generations.
Medium Severity
Password complexity, or strength, is a measure of the effectiveness of a password in resisting attempts at guessing and brute-force attacks. If the information system or application allows the user to consecutively reuse their password when that password has exceeded its defined lifetime, the end result is a password that is not changed as per policy requirements.
SRG-OS-000073-GPOS-00041
1 Rule
SLEM 5 must configure the Linux Pluggable Authentication Modules (PAM) to only store 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.
SRG-OS-000480-GPOS-00227
1 Rule
SLEM 5 must not be configured to allow blank or null passwords.
High 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.
SRG-OS-000480-GPOS-00227
1 Rule
SLEM 5 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 should never be used in operational environments.
SRG-OS-000075-GPOS-00043
1 Rule
SLEM 5 must employ user passwords with a minimum lifetime of 24 hours (one day).
Medium Severity
Enforcing a minimum password lifetime helps 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
SLEM 5 must employ user passwords with a maximum lifetime of 60 days.
Medium Severity
Any password, no matter how complex, can eventually be cracked. Therefore, passwords need to be changed periodically. If SLEM 5 does not limit the lifetime of passwords and force users to change their passwords, there is the risk that SLEM 5 passwords could be compromised.
SRG-OS-000077-GPOS-00045
1 Rule
SLEM 5 must employ a password history file.
Medium Severity
Password complexity, or strength, is a measure of the effectiveness of a password in resisting attempts at guessing and brute-force attacks. If the information system or application allows the user to consecutively reuse their password when that password has exceeded its defined lifetime, the end result is a password that is not changed as per policy requirements.
SRG-OS-000073-GPOS-00041
1 Rule
SLEM 5 must employ FIPS 140-2/140-3-approved cryptographic hashing algorithms for system authentication.
High Severity
The system must use a strong hashing algorithm to store the password. The system must use a sufficient number of hashing rounds to ensure the required level of entropy. 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.
SRG-OS-000073-GPOS-00041
1 Rule
SLEM 5 shadow password suite must be configured to use a sufficient number of hashing rounds.
High Severity
The system must use a strong hashing algorithm to store the password. The system must use a sufficient number of hashing rounds to ensure the required level of entropy. 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.
SRG-OS-000120-GPOS-00061
1 Rule
SLEM 5 must employ FIPS 140-2/140-3 approved cryptographic hashing algorithm for system authentication (login.defs).
Medium Severity
Unapproved mechanisms that are used for authentication to the cryptographic module are not verified and therefore cannot be relied on to provide confidentiality or integrity, and DOD data may be compromised. SLEM 5 using encryption are required to use FIPS 140-2/140-3 compliant mechanisms for authenticating to cryptographic modules. FIPS 140-2/140-3 is the current standard for validating that mechanisms used to access cryptographic modules use authentication that meets DOD requirements. This allows for Security Levels 1, 2, 3, or 4 for use on a general-purpose computing system.
SRG-OS-000075-GPOS-00043
1 Rule
SLEM 5 must be configured to create or update passwords with a minimum lifetime of 24 hours (one day).
Medium Severity
Enforcing a minimum password lifetime helps 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
SLEM 5 must be configured to create or update passwords with a maximum lifetime of 60 days.
Medium Severity
Any password, no matter how complex, can eventually be cracked. Therefore, passwords need to be changed periodically. If SLEM 5 does not limit the lifetime of passwords and force users to change their passwords, there is the risk that SLEM 5 passwords could be compromised.
SRG-OS-000375-GPOS-00160
1 Rule
SLEM 5 must have the packages required for multifactor authentication to be installed.
Medium Severity
Using an authentication device, such as a Common Access Card (CAC) or token 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 (PIV) card and the DOD CAC. A privileged account is defined as an information system account with authorizations of a privileged user. Remote access is access to DOD nonpublic information systems by an authorized user (or an information system) communicating through an external, nonorganization-controlled network. Remote access methods include, for example, dial-up, broadband, and wireless. This requirement only applies to components where this is specific to the function of the device or has the concept of an organizational user (e.g., VPN, proxy capability). This does not apply to authentication for the purpose of configuring the device itself (management).
SRG-OS-000068-GPOS-00036
1 Rule
SLEM 5 must implement multifactor authentication for access to privileged accounts via pluggable authentication modules (PAM).
Medium Severity
Using an authentication device, such as a Common Access Card (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 (PIV) card and the DOD CAC. A privileged account is defined as an information system account with authorizations of a privileged user. Remote access is access to DOD nonpublic information systems by an authorized user (or an information system) communicating through an external, nonorganization-controlled network. Remote access methods include, for example, dial-up, broadband, and wireless. This requirement only applies to components where this is specific to the function of the device or has the concept of an organizational user (e.g., VPN, proxy capability). This does not apply to authentication for the purpose of configuring the device itself (management).
SRG-OS-000375-GPOS-00160
1 Rule
SLEM 5 must implement certificate status checking for multifactor authentication.
Medium Severity
Using an authentication device, such as a Common Access Card (CAC) or token separate from the information system, ensures credentials stored on the authentication device will not be affected if the information system is compromised. Multifactor solutions that require devices separate from information systems to gain access include hardware tokens providing time-based or challenge-response authenticators, and smart cards such as the U.S. Government Personal Identity Verification (PIV) card and the DOD CAC. A privileged account is defined as an information system account with authorizations of a privileged user. Remote access is access to DOD nonpublic information systems by an authorized user (or an information system) communicating through an external, nonorganization-controlled network. Remote access methods include, for example, dial-up, broadband, and wireless. This requirement only applies to components with device-specific functions, or for organizational users (e.g., VPN, proxy capability). This does not apply to authentication for the purpose of configuring the device itself (management).
SRG-OS-000383-GPOS-00166
1 Rule
If Network Security Services (NSS) is being used by SLEM 5 it must prohibit the use of cached authentications after one day.
Medium Severity
If cached authentication information is out of date, the validity of the authentication information may be questionable.
SRG-OS-000383-GPOS-00166
1 Rule
SLEM 5 must configure the Linux Pluggable Authentication Modules (PAM) to prohibit the use of cached offline authentications after one day.
Medium Severity
If cached authentication information is out of date, the validity of the authentication information may be questionable.
SRG-OS-000066-GPOS-00034
1 Rule
SLEM 5, for PKI-based authentication, must validate certificates by constructing a certification path (which includes status information) to an accepted trust anchor.
Medium Severity
Without path validation, an informed trust decision by the relying party cannot be made when presented with any certificate not already explicitly trusted. A trust anchor is an authoritative entity represented via a public key and associated data. It is used in the context of public key infrastructures, X.509 digital certificates, and DNSSEC. When there is a chain of trust, usually the top entity to be trusted becomes the trust anchor; it can be, for example, a Certification Authority (CA). A certification path starts with the subject certificate and proceeds through a number of intermediate certificates up to a trusted root certificate, typically issued by a trusted CA. This requirement verifies that a certification path to an accepted trust anchor is used for certificate validation and that the path includes status information. Path validation is necessary for a relying party to make an informed trust decision when presented with any certificate not already explicitly trusted. Status information for certification paths includes certificate revocation lists or online certificate status protocol responses. Validation of the certificate status information is out of scope for this requirement.
SRG-OS-000480-GPOS-00227
1 Rule
SLEM 5 must be configured to not overwrite Pluggable Authentication Modules (PAM) configuration on package changes.
Medium Severity
The "pam-config" command line utility automatically generates a system PAM configuration as packages are installed, updated, or removed from the system. "pam-config" removes configurations for PAM modules and parameters that it does not know about. It may render ineffective PAM configuration by the system administrator and thus impact system security.
SRG-OS-000363-GPOS-00150
1 Rule
SLEM 5 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 SLEM 5 performing security function verification/testing and/or systems and environments that require this functionality.
SRG-OS-000480-GPOS-00227
1 Rule
SLEM 5 file integrity tool must be configured to verify Access Control Lists (ACLs).
Medium 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
SLEM 5 file integrity tool must be configured to verify extended attributes.
Medium Severity
Extended attributes in file systems are used to contain arbitrary data and file metadata with security implications.
SRG-OS-000278-GPOS-00108
1 Rule
SLEM 5 file integrity tool must be configured to protect the integrity of the audit tools.
Medium Severity
Protecting the integrity of the tools used for auditing purposes is a critical step toward ensuring the integrity of audit information. Audit information includes all information (e.g., audit records, audit settings, and audit reports) needed to successfully audit information system activity. Audit tools include but are not limited to vendor-provided and open-source audit tools needed to successfully view and manipulate audit information system activity and records. Audit tools include custom queries and report generators. It is not uncommon for attackers to replace the audit tools or inject code into the existing tools to provide the capability to hide or erase system activity from the audit logs. To address this risk, audit tools must be cryptographically signed to provide the capability to identify when the audit tools have been modified, manipulated, or replaced. An example is a checksum hash of the file or files.
SRG-OS-000363-GPOS-00150
1 Rule
Advanced Intrusion Detection Environment (AIDE) must verify the baseline SLEM 5 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 SLEM 5. Changes to SLEM 5 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 SLEM 5. SLEM 5's information system security manager (ISSM)/information system security officer (ISSO) and system administrator (SA) must be notified via email and/or monitoring system trap when there is an unauthorized modification of a configuration item.
SRG-OS-000447-GPOS-00201
1 Rule
SLEM 5 must notify the system administrator (SA) when Advanced Intrusion Detection Environment (AIDE) discovers anomalies in the operation of any security functions.
Medium Severity
If anomalies are not acted on, security functions may fail to secure the system. 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. Notifications provided by information systems include messages to local computer consoles and/or hardware indications, such as lights. This capability must take into account operational requirements for availability for selecting an appropriate response. The organization may choose to shut down or restart the information system upon security function anomaly detection.
SRG-OS-000479-GPOS-00224
1 Rule
SLEM 5 must offload rsyslog messages for networked systems in real time and offload standalone systems at least weekly.
Medium Severity
Information stored in one location is vulnerable to accidental or incidental deletion or alteration. Offloading is a common process in information systems with limited audit storage capacity.
SRG-OS-000337-GPOS-00129
1 Rule
SLEM 5 must have the auditing package installed.
Medium Severity
Without establishing what type of events occurred, the source of events, where events occurred, and the outcome of events, it would be difficult to establish, correlate, and investigate the events leading up to an outage or attack. Audit record content that may be necessary to satisfy this requirement includes, for example, time stamps, source and destination addresses, user/process identifiers, event descriptions, success/fail indications, filenames involved, and access control or flow control rules invoked. Associating event types with detected events in SLEM 5 audit logs provides a means of investigating an attack, recognizing resource utilization or capacity thresholds, or identifying an improperly configured SLEM 5.
SRG-OS-000037-GPOS-00015
1 Rule
SLEM 5 audit records must contain information to establish what type of events occurred, the source of events, where events occurred, and the outcome of events.
Medium Severity
Without establishing what type of events occurred, the source of events, where events occurred, and the outcome of events, it would be difficult to establish, correlate, and investigate the events leading up to an outage or attack. 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 SLEM 5 audit logs provides a means of investigating an attack, recognizing resource utilization or capacity thresholds, or identifying an improperly configured SLEM 5.
SRG-OS-000342-GPOS-00133
1 Rule
The audit-audispd-plugins package must be installed on SLEM 5.
Medium Severity
Information stored in one location is vulnerable to accidental or incidental deletion or alteration. Offloading is a common process in information systems with limited audit storage capacity. The auditd service does not include the ability to send audit records to a centralized server for management directly. However, it can use a plug-in for audit event multiplexor to pass audit records to a remote server.
SRG-OS-000341-GPOS-00132
1 Rule
SLEM 5 must allocate audit record storage capacity to store at least one week of audit records when audit records are not immediately sent to a central audit record storage facility.
Medium Severity
To ensure SLEM 5 has a sufficient storage capacity in which to write the audit logs, SLEM 5 must be able to allocate audit record storage capacity. The task of allocating audit record storage capacity is usually performed during initial installation of SLEM 5.
SRG-OS-000343-GPOS-00134
1 Rule
SLEM 5 auditd service must notify the system administrator (SA) and information system security officer (ISSO) immediately when audit storage capacity is 75 percent full.
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-000047-GPOS-00023
1 Rule
SLEM 5 audit system must take appropriate action when the audit storage volume is full.
Medium Severity
It is critical that when SLEM 5 is at risk of failing to process audit logs as required, it takes action to mitigate the failure. Audit processing failures include software/hardware errors, failures in the audit capturing mechanisms, and audit storage capacity being reached or exceeded. Responses to audit failure depend on the nature of the failure mode. When availability is an overriding concern, other approved actions in response to an audit failure are as follows: 1) If the failure was caused by the lack of audit record storage capacity, SLEM 5 must continue generating audit records if possible (automatically restarting the audit service if necessary), overwriting the oldest audit records in a first-in-first-out manner. 2) If audit records are sent to a centralized collection server and communication with this server is lost or the server fails, SLEM 5 must queue audit records locally until communication is restored or until the audit records are retrieved manually. Upon restoration of the connection to the centralized collection server, action should be taken to synchronize the local audit data with the collection server.
SRG-OS-000479-GPOS-00224
1 Rule
SLEM 5 must offload 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. Offloading is a common process in information systems with limited audit storage capacity.
SRG-OS-000479-GPOS-00224
1 Rule
Audispd must take appropriate action when SLEM 5 audit storage is full.
Medium Severity
Information stored in one location is vulnerable to accidental or incidental deletion or alteration. Offloading is a common process in information systems with limited audit storage capacity.
SRG-OS-000057-GPOS-00027
1 Rule
SLEM 5 must protect audit rules from unauthorized modification.
Medium Severity
Without the capability to restrict which roles and individuals can select which events are audited, unauthorized personnel may be able to prevent the auditing of critical events. Misconfigured audits may degrade the system's performance by overwhelming the audit log. Misconfigured audits may also make it more difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one.
SRG-OS-000256-GPOS-00097
1 Rule
SLEM 5 audit tools must have the proper permissions configured to protect against unauthorized access.
Medium Severity
Protecting audit information includes identifying and protecting the tools used to view and manipulate log data. Protecting audit tools is necessary to prevent unauthorized operation on audit information. SLEM 5 providing tools to interface with audit information will leverage user permissions and roles identifying the user accessing the tools and the corresponding rights the user enjoys to make access decisions regarding the access to audit tools. Audit tools include, but are not limited to, vendor-provided and open-source audit tools needed to view and manipulate audit information system activity and records. Audit tools include custom queries and report generators.
SRG-OS-000256-GPOS-00097
1 Rule
SLEM 5 audit tools must have the proper permissions applied to protect against unauthorized access.
Medium Severity
Protecting audit information includes identifying and protecting the tools used to view and manipulate log data. Protecting audit tools is necessary to prevent unauthorized operation on audit information. SLEM 5 providing tools to interface with audit information will leverage user permissions and roles identifying the user accessing the tools and the corresponding rights the user enjoys to make access decisions regarding the access to audit tools. Audit tools include, but are not limited to, vendor-provided and open-source audit tools needed to successfully view and manipulate audit information system activity and records. Audit tools include custom queries and report generators.
SRG-OS-000342-GPOS-00133
1 Rule
SLEM 5 audit event multiplexor must be configured to use Kerberos.
Low Severity
Information stored in one location is vulnerable to accidental or incidental deletion or alteration. Allowing devices and users to connect to or from the system without first authenticating them allows untrusted access and can lead to a compromise or attack. Audit events that may include sensitive data must be encrypted prior to transmission. Kerberos provides a mechanism to provide both authentication and encryption for audit event records.
SRG-OS-000342-GPOS-00133
1 Rule
Audispd must offload audit records onto a different system or media from SLEM 5 being audited.
Medium Severity
Information stored in one location is vulnerable to accidental or incidental deletion or alteration. Offloading is a common process in information systems with limited audit storage capacity.
SRG-OS-000046-GPOS-00022
1 Rule
The information system security officer (ISSO) and system administrator (SA), at a minimum, must have mail aliases to be notified of a SLEM 5 audit processing failure.
Medium Severity
It is critical for the appropriate personnel to be aware if a system is at risk of failing to process audit logs as required. Without this notification, the security personnel may be unaware of an impending failure of the audit capability, and system operation may be adversely affected. Audit processing failures include software/hardware errors, failures in the audit capturing mechanisms, and audit storage capacity being reached or exceeded. This requirement applies to each audit data storage repository (i.e., distinct information system component where audit records are stored), the centralized audit storage capacity of organizations (i.e., all audit data storage repositories combined), or both.
SRG-OS-000046-GPOS-00022
1 Rule
The information system security officer (ISSO) and system administrator (SA), at a minimum, must be alerted of a SLEM 5 audit processing failure event.
Medium Severity
It is critical for the appropriate personnel to be aware if a system is at risk of failing to process audit logs as required. Without this notification, the security personnel may be unaware of an impending failure of the audit capability, and system operation may be adversely affected. Audit processing failures include software/hardware errors, failures in the audit capturing mechanisms, and audit storage capacity being reached or exceeded. This requirement applies to each audit data storage repository (i.e., distinct information system component where audit records are stored), the centralized audit storage capacity of organizations (i.e., all audit data storage repositories combined), or both.
SRG-OS-000037-GPOS-00015
1 Rule
SLEM 5 must generate audit records for all uses of the "chacl" command.
Medium Severity
Without generating audit records specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter).
SRG-OS-000037-GPOS-00015
1 Rule
SLEM 5 must generate audit records for all uses of the "chage" command.
Medium Severity
Without generating audit records specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter).
SRG-OS-000037-GPOS-00015
1 Rule
SLEM 5 must generate audit records for 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).
SRG-OS-000037-GPOS-00015
1 Rule
SLEM 5 must generate audit records for all uses of the "chfn" 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.
SRG-OS-000037-GPOS-00015
1 Rule
SLEM 5 must generate audit records for all uses of the "chmod" 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).
SRG-OS-000037-GPOS-00015
1 Rule
SLEM 5 must generate audit records for a 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 commands. The organization must maintain audit trails in sufficient detail to reconstruct events to determine the cause and impact of compromise.
SRG-OS-000037-GPOS-00015
1 Rule
SLEM 5 must generate audit records for all uses of the "crontab" command.
Medium Severity
Without generating audit records specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter).
SRG-OS-000037-GPOS-00015
1 Rule
SLEM 5 must generate audit records for 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 commands. The organization must maintain audit trails in sufficient detail to reconstruct events to determine the cause and impact of compromise.
SRG-OS-000037-GPOS-00015
1 Rule
SLEM 5 must generate audit records for all uses of the "insmod" command.
Medium Severity
Without the capability to generate audit records, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). The list of audited events is the set of events for which audits are to be generated. This set of events is typically a subset of the list of all events for which the system is capable of generating audit records. DOD has defined the following list of events for which SLEM 5 will provide an audit record generation capability: 1) Successful and unsuccessful attempts to access, modify, or delete privileges, security objects, security levels, or categories of information (e.g., classification levels); 2) Access actions, such as successful and unsuccessful logon attempts, privileged activities or other system-level access, starting and ending time for user access to the system, concurrent logons from different workstations, successful and unsuccessful accesses to objects, all program initiations, and all direct access to the information system; 3) All account creations, modifications, disabling, and terminations; and 4) All kernel module load, unload, and restart actions.
SRG-OS-000037-GPOS-00015
1 Rule
SLEM 5 must generate audit records for all uses of the "kmod" command.
Medium Severity
Without the capability to generate audit records, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). The list of audited events is the set of events for which audits are to be generated. This set of events is typically a subset of the list of all events for which the system is capable of generating audit records. DOD has defined the following list of events for which SLEM 5 will provide an audit record generation capability: 1) Successful and unsuccessful attempts to access, modify, or delete privileges, security objects, security levels, or categories of information (e.g., classification levels); 2) Access actions, such as successful and unsuccessful logon attempts, privileged activities or other system-level access, starting and ending time for user access to the system, concurrent logons from different workstations, successful and unsuccessful accesses to objects, all program initiations, and all direct access to the information system; 3) All account creations, modifications, disabling, and terminations; and 4) All kernel module load, unload, and restart actions.
SRG-OS-000037-GPOS-00015
1 Rule
SLEM 5 must generate audit records for all uses of the "modprobe" command.
Medium Severity
Without the capability to generate audit records, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). The list of audited events is the set of events for which audits are to be generated. This set of events is typically a subset of the list of all events for which the system is capable of generating audit records. DOD has defined the following list of events for which SLEM 5 will provide an audit record generation capability: 1) Successful and unsuccessful attempts to access, modify, or delete privileges, security objects, security levels, or categories of information (e.g., classification levels); 2) Access actions, such as successful and unsuccessful logon attempts, privileged activities or other system-level access, starting and ending time for user access to the system, concurrent logons from different workstations, successful and unsuccessful accesses to objects, all program initiations, and all direct access to the information system; 3) All account creations, modifications, disabling, and terminations; and 4) All kernel module load, unload, and restart actions.
SRG-OS-000037-GPOS-00015
1 Rule
SLEM 5 must generate audit records for 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 commands. The organization must maintain audit trails in sufficient detail to reconstruct events to determine the cause and impact of compromise.
SRG-OS-000037-GPOS-00015
1 Rule
SLEM 5 must generate audit records for 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. Audit records can be generated from various components within the information system (e.g., module or policy filter).
SRG-OS-000037-GPOS-00015
1 Rule
SLEM 5 must generate audit records for 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 commands. The organization must maintain audit trails in sufficient detail to reconstruct events to determine the cause and impact of compromise.
SRG-OS-000037-GPOS-00015
1 Rule
SLEM 5 must generate audit records for all uses of the "rm" 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).
SRG-OS-000037-GPOS-00015
1 Rule
SLEM 5 must generate audit records for all uses of the "rmmod" command.
Medium Severity
Without the capability to generate audit records, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). The list of audited events is the set of events for which audits are to be generated. This set of events is typically a subset of the list of all events for which the system is capable of generating audit records. DOD has defined the following list of events for which SLEM 5 will provide an audit record generation capability: 1) Successful and unsuccessful attempts to access, modify, or delete privileges, security objects, security levels, or categories of information (e.g., classification levels); 2) Access actions, such as successful and unsuccessful logon attempts, privileged activities or other system-level access, starting and ending time for user access to the system, concurrent logons from different workstations, successful and unsuccessful accesses to objects, all program initiations, and all direct access to the information system; 3) All account creations, modifications, disabling, and terminations; and 4) All kernel module load, unload, and restart actions.
SRG-OS-000037-GPOS-00015
1 Rule
SLEM 5 must generate audit records for all uses of the "setfacl" command.
Medium Severity
Without generating audit records specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter).
SRG-OS-000037-GPOS-00015
1 Rule
SLEM 5 must generate audit records for all uses of the "ssh-agent" 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.
SRG-OS-000037-GPOS-00015
1 Rule
SLEM 5 must generate audit records for 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 commands. The organization must maintain audit trails in sufficient detail to reconstruct events to determine the cause and impact of compromise.
SRG-OS-000037-GPOS-00015
1 Rule
SLEM 5 must generate audit records for all uses of the "su" 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).
SRG-OS-000037-GPOS-00015
1 Rule
SLEM 5 must generate audit records for 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 commands. The organization must maintain audit trails in sufficient detail to reconstruct events to determine the cause and impact of compromise.
SRG-OS-000037-GPOS-00015
1 Rule
SLEM 5 must generate audit records for all uses of the "sudoedit" command.
Medium Severity
Without generating audit records specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter).
SRG-OS-000037-GPOS-00015
1 Rule
SLEM 5 must generate audit records for all uses of the "unix_chkpwd" or "unix2_chkpwd" commands.
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-000037-GPOS-00015
1 Rule
SLEM 5 must generate audit records for all uses of the "usermod" command.
Medium Severity
Without generating audit records specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter).
SRG-OS-000004-GPOS-00004
1 Rule
SLEM 5 must generate audit records for all account creations, modifications, disabling, and termination events that affect /etc/group.
Medium Severity
Once an attacker establishes initial access to a system, the attacker often attempts to create a persistent method of reestablishing access. One way to accomplish this is for the attacker to simply create a new account. Auditing account creation mitigates this risk. To address access requirements, SLEM 5 may be integrated with enterprise-level authentication/access/auditing mechanisms that meet or exceed access control policy requirements.
SRG-OS-000004-GPOS-00004
1 Rule
SLEM 5 must generate audit records for all account creations, modifications, disabling, and termination events that affect /etc/security/opasswd.
Medium Severity
Once an attacker establishes initial access to a system, the attacker often attempts to create a persistent method of reestablishing access. One way to accomplish this is for the attacker to simply create a new account. Auditing account creation mitigates this risk. To address access requirements, SLEM 5 may be integrated with enterprise-level authentication/access/auditing mechanisms that meet or exceed access control policy requirements.
SRG-OS-000004-GPOS-00004
1 Rule
SLEM 5 must generate audit records for all account creations, modifications, disabling, and termination events that affect /etc/passwd.
Medium Severity
Once an attacker establishes initial access to a system, the attacker often attempts to create a persistent method of reestablishing access. One way to accomplish this is for the attacker to simply create a new account. Auditing account creation mitigates this risk. To address access requirements, SLEM 5 may be integrated with enterprise-level authentication/access/auditing mechanisms that meet or exceed access control policy requirements.
SRG-OS-000004-GPOS-00004
1 Rule
SLEM 5 must generate audit records for all account creations, modifications, disabling, and termination events that affect /etc/shadow.
Medium Severity
Once an attacker establishes initial access to a system, the attacker often attempts to create a persistent method of reestablishing access. One way to accomplish this is for the attacker to simply create a new account. Auditing account creation mitigates this risk. To address access requirements, SLEM 5 may be integrated with enterprise-level authentication/access/auditing mechanisms that meet or exceed access control policy requirements.
SRG-OS-000037-GPOS-00015
1 Rule
SLEM 5 must generate audit records for all uses of the "chmod", "fchmod" and "fchmodat" system calls.
Medium Severity
Without generating audit records specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). The system call rules are loaded into a matching engine that intercepts each syscall made by all programs on the system. Therefore, it is important to use syscall rules only when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. However, the performance can be helped by combining syscalls into one rule whenever possible.
SRG-OS-000037-GPOS-00015
1 Rule
SLEM 5 must generate audit records for all uses of the "chown", "fchown", "fchownat", and "lchown" system calls.
Medium Severity
Without generating audit records specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). 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.
SRG-OS-000037-GPOS-00015
1 Rule
SLEM 5 must generate audit records for all uses of the "creat", "open", "openat", "open_by_handle_at", "truncate", and "ftruncate" system calls.
Medium Severity
Without generating audit records specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). 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.
SRG-OS-000037-GPOS-00015
1 Rule
SLEM 5 must generate audit records for all uses of the "delete_module" system call.
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-000037-GPOS-00015
1 Rule
SLEM 5 must generate audit records for all uses of the "init_module" and "finit_module" system calls.
Medium Severity
Without generating audit records specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). 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.
SRG-OS-000037-GPOS-00015
1 Rule
SLEM 5 must generate audit records for all uses of the "mount" system call.
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.
SRG-OS-000037-GPOS-00015
1 Rule
SLEM 5 must generate audit records for all uses of the "setxattr", "fsetxattr", "lsetxattr", "removexattr", "fremovexattr", and "lremovexattr" system calls.
Medium Severity
Without generating audit records specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). 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.
SRG-OS-000037-GPOS-00015
1 Rule
SLEM 5 must generate audit records for all uses of the "umount" system call.
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.
SRG-OS-000468-GPOS-00212
1 Rule
SLEM 5 must generate audit records for all uses of the "unlink", "unlinkat", "rename", "renameat", and "rmdir" system calls.
Medium Severity
Without generating audit records specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). 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.
SRG-OS-000327-GPOS-00127
1 Rule
SLEM 5 must generate audit records for all uses 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-000037-GPOS-00015
1 Rule
SLEM 5 must generate audit records for all modifications to the "lastlog" file.
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-000037-GPOS-00015
1 Rule
SLEM 5 must generate audit records for all modifications to the "tallylog" file must generate an audit record.
Medium Severity
Without generating audit records specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter).
SRG-OS-000037-GPOS-00015
1 Rule
SLEM 5 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.
SRG-OS-000062-GPOS-00031
1 Rule
Successful/unsuccessful uses of "setfiles" in SLEM 5 must generate an audit record.
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. The "setfiles" command is primarily used to initialize the security context fields (extended attributes) on one or more filesystems (or parts of them). Usually it is initially run as part of the SELinux installation process (a step commonly known as labeling). 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-000062-GPOS-00031
1 Rule
Successful/unsuccessful uses of "semanage" in SLEM 5 must generate an audit record.
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. The "semanage" command is used to configure certain elements of SELinux policy without requiring modification to or recompilation from policy sources. 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-000062-GPOS-00031
1 Rule
Successful/unsuccessful uses of "setsebool" in SLEM 5 must generate an audit record.
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. The "setsebool" command sets the current state of a particular SELinux boolean or a list of booleans to a given value. 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-000472-GPOS-00217
1 Rule
SLEM 5 must generate audit records for the "/run/utmp file".
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-000472-GPOS-00217
1 Rule
SLEM 5 must generate audit records for the "/var/log/btmp" file.
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-000472-GPOS-00217
1 Rule
SLEM 5 must generate audit records for the "/var/log/wtmp" file.
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-000480-GPOS-00227
1 Rule
SLEM 5 must not disable syscall auditing.
Medium Severity
By default, SLEM 5 includes the "-a task,never" audit rule as a default. This rule suppresses syscall auditing for all tasks started with this rule in effect. Because the audit daemon processes the "audit.rules" file from the top down, this rule supersedes all other defined syscall rules; therefore no syscall auditing can take place on the operating system.
SRG-OS-000396-GPOS-00176
1 Rule
FIPS 140-2/140-3 mode must be enabled on SLEM 5.
High Severity
Use of weak or untested encryption algorithms undermines the purposes of using encryption to protect data. SLEM 5 must implement cryptographic modules adhering to the higher standards approved by the federal government since this provides assurance they have been tested and validated.
SRG-OS-000480-GPOS-00227
1 Rule
SLEM 5 must be a vendor-supported release.
High Severity
A SLEM 5 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.