STIGQter: STIG Summary: Red Hat Enterprise Linux 9 Security Technical Implementation Guide Version: 2 Release: 9 Benchmark Date: 01 Jul 2026:

RHEL 9 must restrict access to the kernel message buffer.

DISA Rule

SV-257797r1198253_rule

Vulnerability Number

V-257797

Group Title

SRG-OS-000132-GPOS-00067

Rule Version

RHEL-09-213010

Severity

CAT II

CCI(s)

• CCI-001082 - Separate user functionality, including user interface services, from system management functionality.
• CCI-001090 - Prevent unauthorized and unintended information transfer via shared system resources.

Weight

10

Fix Recommendation

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

Create a drop-in if it does not already exist:

$ sudo vi /etc/sysctl.d/99-dmesg_restrict.conf

Add the following to the file:
kernel.dmesg_restrict = 1

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

$ sudo sysctl --system

Check Contents

Verify RHEL 9 is configured to restrict access to the kernel message buffer.

Check the status of the "kernel.dmesg_restrict" kernel parameter with the following command:

$ 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.

Vulnerability Number

V-257797

Documentable

False

Rule Version

RHEL-09-213010

Severity Override Guidance

Verify RHEL 9 is configured to restrict access to the kernel message buffer.

Check the status of the "kernel.dmesg_restrict" kernel parameter with the following command:

$ 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 Content Reference

M

Target Key

5551