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Restrict Access to Kernel Message Buffer

An XCCDF Rule

Description

To set the runtime status of the kernel.dmesg_restrict kernel parameter, run the following command:

$ sudo sysctl -w kernel.dmesg_restrict=1
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d:
kernel.dmesg_restrict = 1

Rationale

Unprivileged access to the kernel syslog can expose sensitive kernel address information.

ID
xccdf_org.ssgproject.content_rule_sysctl_kernel_dmesg_restrict
Severity
Low
References
Updated



Remediation - Ansible

- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - CCE-80913-7
  - DISA-STIG-RHEL-08-010375

Remediation - Kubernetes Patch

---
apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  config:
    ignition:

Remediation - Shell Script

# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel; then

# Comment out any occurrences of kernel.dmesg_restrict from /etc/sysctl.d/*.conf files

for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf; do