SLEM 5 must restrict access to the kernel message buffer.
Overview
| Finding ID | Version | Rule ID | IA Controls | Severity |
| V-261269 | SLEM-05-213010 | SV-261269r996301_rule | CCI-001090 | medium |
| Description | ||||
| Restricting access to the kernel message buffer limits access only to root. This prevents attackers from gaining additional system information as a nonprivileged user. | ||||
| STIG | Date | |||
| SUSE Linux Enterprise Micro (SLEM) 5 Security Technical Implementation Guide | 2025-05-08 | |||
Details
Check Text (C-261269r996301_chk)
Verify SLEM 5 is configured to restrict access to the kernel message buffer with the following commands:
> sudo sysctl kernel.dmesg_restrict
kernel.dmesg_restrict = 1
If "kernel.dmesg_restrict" is not set to "1" or is missing, this is a finding.
Check that the configuration files are present to enable this kernel parameter:
> sudo grep -r kernel.dmesg_restrict /run/sysctl.d/* /etc/sysctl.d/* /usr/local/lib/sysctl.d/* /usr/lib/sysctl.d/* /lib/sysctl.d/* /etc/sysctl.conf 2> /dev/null
/etc/sysctl.conf:kernel.dmesg_restrict = 1
/etc/sysctl.d/99-sysctl.conf:kernel.dmesg_restrict = 1
If "kernel.dmesg_restrict" is not set to "1", is missing or commented out, this is a finding.
If conflicting results are returned, this is a finding.
Fix Text (F-64906r996300_fix)
Configure SLEM 5 to restrict access to the kernel message buffer.
Set the system to the required kernel parameter by adding or modifying the following line in /etc/sysctl.conf or a config file in the /etc/sysctl.d/ directory:
kernel.dmesg_restrict = 1
Remove any configurations that conflict with the above from the following locations:
/run/sysctl.d/
/etc/sysctl.d/
/usr/local/lib/sysctl.d/
/usr/lib/sysctl.d/
/lib/sysctl.d/
/etc/sysctl.conf
Reload settings from all system configuration files with the following command:
$ sudo sysctl --system