RHEL-09-213010 - RHEL 9 must restrict access to the kernel message buffer.

Information

Preventing unauthorized information transfers mitigates the risk of information, including encrypted representations of information, produced by the actions of prior users/roles (or the actions of processes acting on behalf of prior users/roles) from being available to any current users/roles (or current processes) that obtain access to shared system resources (e.g., registers, main memory, hard disks) after those resources have been released back to information systems. The control of information in shared resources is also commonly referred to as object reuse and residual information protection.

This requirement generally applies to the design of an information technology product, but it can also apply to the configuration of particular information system components that are, or use, such products. This can be verified by acceptance/validation processes in DOD or other government agencies.

There may be shared resources with configurable protections (e.g., files in storage) that may be assessed on specific information system components.

Restricting access to the kernel message buffer limits access to only root. This prevents attackers from gaining additional system information as a nonprivileged user.

Satisfies: SRG-OS-000132-GPOS-00067, SRG-OS-000138-GPOS-00069

Solution

Configure RHEL 9 to restrict access to the kernel message buffer.

Add or edit the following line in a system configuration file, in the '/etc/sysctl.d/' directory:

kernel.dmesg_restrict = 1

Load settings from all system configuration files with the following command:

$ sudo sysctl --system

See Also

https://dl.dod.cyber.mil/wp-content/uploads/stigs/zip/U_RHEL_9_V2R1_STIG.zip

Item Details

Category: SYSTEM AND COMMUNICATIONS PROTECTION

References: 800-53|SC-2, 800-53|SC-4, CAT|II, CCI|CCI-001082, CCI|CCI-001090, Rule-ID|SV-257797r958514_rule, STIG-ID|RHEL-09-213010, Vuln-ID|V-257797

Plugin: Unix

Control ID: 8db4e9d306e8ccc172d43f5415a1fb03a74907cf151e634412a20c01a9c34b20