SV-257785r1044833: The x86 Ctrl-Alt-Delete key sequence must be disabled on RHEL 9. | Red Hat Enterprise Linux 9 STIG SCAP Benchmark

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Assessment Title

Rule Text

The x86 Ctrl-Alt-Delete key sequence must be disabled on RHEL 9.

Description

Discussion Text

A locally logged-on user who presses Ctrl-Alt-Delete when at the console can reboot the system. If accidentally pressed, as could happen in the case of a mixed OS environment, this can create the risk of short-term loss of availability of systems due to unintentional reboot. In a graphical user environment, risk of unintentional reboot from the Ctrl-Alt-Delete sequence is reduced because the user will be prompted before any action is taken. Satisfies: SRG-OS-000324-GPOS-00125, SRG-OS-000480-GPOS-00227

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

IA Controls

NIST SP 800-53

Not mappedCCI-002235

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:257785
# The x86 Ctrl-Alt-Delete key sequence must be disabled on RHEL 9.
# Per-module read mechanism curated from static teardown of DISA's SCC tool
# (SCAP Compliance Checker) -- see the SCC Automation Reference above.

# ctrl-alt-del.target LoadState is masked if it exists.
# systemdunitproperty_object (systemdunitproperty_test)
test_1() {
  (systemctl show -p 'LoadState' --value 'ctrl-alt-del.target') | grep -qxF 'masked'
}
# ctrl-alt-del.target UnitFileState is masked if it exists.
# systemdunitproperty_object (systemdunitproperty_test)
test_2() {
  (systemctl show -p 'UnitFileState' --value 'ctrl-alt-del.target') | grep -qxF 'masked'
}

if ( test_1 && test_2 ); 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
# OVAL Definition: oval:mil.disa.stig.rhel9os:def:257785
if ! command -v systemctl &> /dev/null; then
    echo "FAIL"
    exit 1
fi
if [ "$(systemctl is-enabled ctrl-alt-del.target)" = "enabled" ] && [ "$(systemctl is-masked ctrl-alt-del.target)" = "masked" ]; then
    echo "PASS"
else
    echo "FAIL"
fi
exit 0

Remediation

Configure RHEL 9 to disable the ctrl-alt-del.target with the following command:

$ sudo systemctl disable --now ctrl-alt-del.target
$ sudo systemctl mask --now ctrl-alt-del.target