SV-258026r1045103: RHEL 9 must prevent a user from overriding the session lock-delay setting for the graphical user interface. | Red Hat Enterprise Linux 9 STIG SCAP Benchmark

Loading benchmark…

Assessment Title

Rule Text

RHEL 9 must prevent a user from overriding the session lock-delay setting for the graphical user interface.

Description

Discussion Text

A session time-out lock is a temporary action taken when a user stops work and moves away from the immediate physical vicinity of the information system but does not logout because of the temporary nature of the absence. Rather than relying on the user to manually lock their operating system session prior to vacating the vicinity, the GNOME desktop can be configured to identify when a user's session has idled and take action to initiate the session lock. As such, users should not be allowed to change session settings.

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

IA Controls

NIST SP 800-53

Not mappedCCI-000057

References

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

Checks

DISA STIG (Manual Reference)

Note: This requirement assumes the use of the RHEL 9 default graphical user interface, the GNOME desktop environment. If the system does not have any graphical user interface installed, this requirement is Not Applicable.

Verify RHEL 9 prevents a user from overriding settings for graphical user interfaces. 

$ gsettings writable org.gnome.desktop.screensaver lock-delay
 
false
 
If "lock-delay" is writable and the result is "true", this is a finding.

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:258026
# RHEL 9 must prevent a user from overriding the session lock-delay setting 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.
#
# MANUAL REVIEW REQUIRED -- the module(s) below could not be reconstructed
# into working code from curated SCC reference data, and are excluded from
# the automated result:
#   - textfilecontent54_object (textfilecontent54_test) -- /org/gnome/desktop/screensaver/lock-delay in dconf user database locks directories exists: cannot derive an existence probe for this object type

# dconf user database(s) exist
# textfilecontent54_object (textfilecontent54_test)
test_1() {
  grep -Pq '^system-db:(\S+)\s*$' '/etc/dconf/profile/user' &>/dev/null
}

if test_1; then
  echo "PASS (automated portion only -- MANUAL REVIEW still required, see notes above)"
else
  echo "FAIL (or see MANUAL REVIEW note above)"
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:258026

if [ -d /etc/dconf/profile ]; then
  dconf_profile=$(find /etc/dconf/profile -maxdepth 1 -type d -name 'user' | wc -l)
  if [ $dconf_profile -ge 1 ]; then
    dconf_db=$(find /etc/dconf/profile/user -maxdepth 1 -type d -name 'system-db' | wc -l)
    if [ $dconf_db -eq 0 ]; then
      echo "FAIL"
      exit 1
    fi
    grep -q "^/org/gnome/desktop/screensaver/lock-delay$" /etc/dconf/db/local.d/locks/session || { echo "FAIL"; exit 1; }
  else
    echo "FAIL"
    exit 1
  fi
else
  echo "FAIL"
  exit 1
fi

echo "PASS"
exit 0

Remediation

Configure RHEL 9 to prevent a user from overriding settings for graphical user interfaces.

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

Note: The example below is using the database "local" for the system. If the system is using another database in "/etc/dconf/profile/user", the file should be created under the appropriate subdirectory.

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

Add the following setting to prevent nonprivileged users from modifying it:

/org/gnome/desktop/screensaver/lock-delay

Run the following command to update the database:

$ sudo dconf update