SV-204396r958400: The Red Hat Enterprise Linux operating system must enable a user session lock until that user re-establishes access using established identification and authentication procedures. | Red Hat Enterprise Linux 7 STIG SCAP Benchmark

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Assessment Title

Rule Text

The Red Hat Enterprise Linux operating system must enable a user session lock until that user re-establishes access using established identification and authentication procedures.

Description

Discussion Text

A session 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 want to log out because of the temporary nature of the absence. The session lock is implemented at the point where session activity can be determined. Regardless of where the session lock is determined and implemented, once invoked, the session lock must remain in place until the user reauthenticates. No other activity aside from reauthentication must unlock the system. Satisfies: SRG-OS-000028-GPOS-00009, SRG-OS-000030-GPOS-00011

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

IA Controls

NIST SP 800-53

Not mappedCCI-000056SV-86515V-71891

References

DPMS Target Red Hat Enterprise Linux 7 DISA DPMS Target Red Hat Enterprise Linux 7 2899

Checks

DISA STIG (Manual Reference)

Verify the operating system enables a user's session lock until that user re-establishes access using established identification and authentication procedures.

Note: If the system does not have GNOME installed, this requirement is Not Applicable.

Check to see if the screen lock is enabled with the following command:

     # grep -ir lock-enabled /etc/dconf/db/local.d/ | grep -v locks
     lock-enabled=true

If the "lock-enabled" setting is missing or is not set to "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.rhel7:def:988
# The Red Hat Enterprise Linux operating system must enable a user session lock until that user re-establishes access using established identification and authentication procedures.
# 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) -- screensaver lock is enabled: cannot derive an existence probe for this object type

# package dconf is installed
# rpminfo_object (rpminfo_test)
test_1() {
  rpm -q --quiet 'dconf' &>/dev/null
}
# package dconf is installed
# rpminfo_object (rpminfo_test)
test_2() {
  rpm -q --quiet 'dconf' &>/dev/null
}
# dconf user profile exists
# textfilecontent54_object (textfilecontent54_test)
test_3() {
  grep -Pq '^user-db:user\nsystem-db:local$' '/etc/dconf/profile/user' &>/dev/null
}

if ( test_1 || ( test_2 || test_3 ) ); 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:mil.disa.stig.rhel7:def:988

if ! command -v rpm &> /dev/null; then
    echo "FAIL"
    exit 1
fi

if rpm -qa | grep -q dconf; then
    if [ ! -f "/etc/dconf/db/local.d/00-screensaver" ]; then
        touch /etc/dconf/db/local.d/00-screensaver
    fi
    if ! grep -q "^[org/gnome/desktop/screensaver]" /etc/dconf/db/local.d/00-screensaver; then
        echo "[org/gnome/desktop/screensaver]" >> /etc/dconf/db/local.d/00-screensaver
        echo "lock-enabled=true" >> /etc/dconf/db/local.d/00-screensaver
    fi
else
    echo "FAIL"
    exit 1
fi

if [ ! -d "/etc/dconf/profile" ]; then
    echo "FAIL"
    exit 1
fi

if grep -q "^user-db:user\\nsystem-db:local$" /etc/dconf/profile/user; then
    if grep -q "^\\[org/gnome/desktop/screensaver\\]([^\\n]*\\n+)+?lock-enabled\\s*=\\s*true\\s*$" /etc/dconf/db/local.d/00-screensaver; then
        echo "PASS"
        exit 0
    else
        echo "FAIL"
        exit 1
    fi
else
    echo "PASS"
    exit 0
fi

Remediation

Configure the operating system to enable a user's session lock until that user re-establishes access using established identification and authentication procedures.

Create a database to contain the system-wide screensaver settings (if it does not already exist) with the following example:

     # touch /etc/dconf/db/local.d/00-screensaver

Edit the "[org/gnome/desktop/screensaver]" section of the database file and add or update the following lines:

     # Set this to true to lock the screen when the screensaver activates
     lock-enabled=true

Update the system databases:

     # dconf update

Users must log out and back in again before the system-wide settings take effect.