SV-252963r991589: The x86 Ctrl-Alt-Delete key sequence in TOSS must be disabled if a graphical user interface is installed. | Tri-Lab Operating System Stack (TOSS) 4 STIG SCAP Benchmark

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Assessment Title

Rule Text

The x86 Ctrl-Alt-Delete key sequence in TOSS must be disabled if a graphical user interface is installed.

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.

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

IA Controls

NIST SP 800-53

Not mappedCCI-000366

References

DPMS Target TOSS 4 DISA DPMS Target TOSS 4 5469

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.toss4os:def:252963
# The x86 Ctrl-Alt-Delete key sequence in TOSS must be disabled if a graphical user interface is installed.
# Per-module read mechanism curated from static teardown of DISA's SCC tool
# (SCAP Compliance Checker) -- see the SCC Automation Reference above.

# logout key is set to an empty string
# textfilecontent54_object (textfilecontent54_test)
test_1() {
  (grep -rhP --include='*' '^\s*\[org/gnome/settings-daemon/plugins/media-keys\]\s+[^\[\]]*^\s*logout=(\S+)\s*$' '/etc/dconf/db/local.d' | sed -En 's/^\s*\[org\/gnome\/settings-daemon\/plugins\/media-keys\]\s+[^\[\]]*^\s*logout=(\S+)\s*$/\1/p') | grep -qxF ''\'''\'''
}

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
# OVAL Definition: oval:mil.disa.stig.toss4os:def:252963
if [ ! -d "/etc/dconf/db/local.d" ]; then echo "PASS"; exit 0; fi
for file in /etc/dconf/db/local.d/*.d; do
    if [ "$(grep -E '^\\s*\\[org/gnome/settings-daemon/plugins/media-keys\\]\\s+logout=\\S+\\s*$' "$file" || true)" = "" ]; then
        echo "PASS"; exit 0;
    fi
done
echo "FAIL"; exit 1

Remediation

Configure the system to disable the Ctrl-Alt-Delete sequence when using a graphical user interface by creating or editing the /etc/dconf/db/local.d/00-disable-CAD file.

Add the setting to disable the Ctrl-Alt-Delete sequence for a graphical user interface:

[org/gnome/settings-daemon/plugins/media-keys]
logout=''

Note: The value above is set to two single quotations.

Then update the dconf settings:

$ sudo dconf update