SV-258032r1045117: RHEL 9 must prevent a user from overriding the Ctrl-Alt-Del sequence settings for the graphical user interface. | Red Hat Enterprise Linux 9 STIG SCAP Benchmark

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Assessment Title

Rule Text

RHEL 9 must prevent a user from overriding the Ctrl-Alt-Del sequence settings for the graphical user interface.

Description

Discussion Text

A locally logged-in user who presses Ctrl-Alt-Del, when at the console, can reboot the system. If accidentally pressed, as could happen in the case of mixed OS environment, this can create the risk of short-term loss of availability of systems due to unintentional reboot.

How this relates to the STIG checklist: STIG vs SCAP benchmark.

IA Controls

NIST SP 800-53

Not mappedCCI-000366

References

DPMS Target Red Hat Enterprise Linux 9 DISA DPMS Target Red Hat Enterprise Linux 9 5551

SCC Automation Reference

The reconstructed evaluation script behind this rule's OVAL check(s) — every module a compound check combines, with this rule's own concrete values and DISA's SCC tool's real per-module mechanism curated from static teardown of SCC releases.

#!/bin/bash
# Reconstructed from oval:mil.disa.stig.rhel9os:def:258032
# RHEL 9 must prevent a user from overriding the Ctrl-Alt-Del sequence settings for the graphical user interface.
# Per-module read mechanism curated from static teardown of DISA's SCC tool
# (SCAP Compliance Checker) -- see the SCC Automation Reference above.

# /org/gnome/settings-daemon/plugins/media-keys/logout is locked in /etc/dconf/db/local.d/locks/*
# textfilecontent54_object (textfilecontent54_test)
test_1() {
  grep -rqP --include='*' '^/org/gnome/settings-daemon/plugins/media-keys/logout$' '/etc/dconf/db/local.d/locks' &>/dev/null
}

if test_1; then
  echo "PASS"
else
  echo "FAIL"
fi

Assessment Script Powered by AISandbox-executed

A standalone Shell script to assess this control automatically. Review before running it in your environment.

Syntax-checked and actually executed in an isolated sandbox (not the real system this checks) — confirmed to run without errors.

#!/bin/sh
# DISA STIG / SCAP compliance check: oval:mil.disa.stig.rhel9os:def:258032

if [ ! -d "/etc/dconf/db/local.d/locks" ]; then echo "FAIL"; exit 1; fi
if [ ! -f "/etc/dconf/db/local.d/locks/session" ]; then echo "FAIL"; exit 1; fi
if grep -q "^/org/gnome/settings-daemon/plugins/media-keys/logout$" /etc/dconf/db/local.d/locks/session; then echo "PASS"; exit 0; fi
echo "FAIL"; exit 1

Remediation

Configure RHEL 9 to disallow the user changing the Ctrl-Alt-Del sequence in the GNOME desktop.

Create a database to contain the systemwide graphical user logon settings (if it does not already exist) with the following command:

$ sudo touch /etc/dconf/db/local.d/locks/session

Add the following line to the session locks file to prevent nonprivileged users from modifying the Ctrl-Alt-Del setting:

/org/gnome/settings-daemon/plugins/media-keys/logout

Run the following command to update the database:

$ sudo dconf update