Enable GNOME3 Screensaver Lock After Idle Period

An XCCDF Rule

Description

To activate locking of the screensaver in the GNOME3 desktop when it is activated, add or set lock-enabled to true in /etc/dconf/db/local.d/00-security-settings. For example:

[org/gnome/desktop/screensaver]
lock-enabled=true

Once the settings have been added, add a lock to /etc/dconf/db/local.d/locks/00-security-settings-lock to prevent user modification. For example:

/org/gnome/desktop/screensaver/lock-enabled

After the settings have been set, run dconf update.

Rationale

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 logout because of the temporary nature of the absense.

ID: xccdf_org.ssgproject.content_rule_dconf_gnome_screensaver_lock_enabled
Severity: Medium
References: 1 12 15 16

5.5.5

DSS05.04 DSS05.10 DSS06.10

3.1.10

CCI-000056 CCI-000058 CCI-000060

4.3.3.6.1 4.3.3.6.2 4.3.3.6.3 4.3.3.6.4 4.3.3.6.5 4.3.3.6.6 4.3.3.6.7 4.3.3.6.8 4.3.3.6.9

SR 1.1 SR 1.10 SR 1.2 SR 1.5 SR 1.7 SR 1.8 SR 1.9

A.18.1.4 A.9.2.1 A.9.2.4 A.9.3.1 A.9.4.2 A.9.4.3

CM-6(a)

PR.AC-7

FMT_MOF_EXT.1

Req-8.1.8

8.2.8

SRG-OS-000028-GPOS-00009 SRG-OS-000030-GPOS-00011

SV-204396r880746_rule
Updated: about 1 year ago

- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - CJIS-5.5.5
  - DISA-STIG-RHEL-07-010060  - NIST-800-171-3.1.10
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-8.1.8
  - PCI-DSSv4-8.2.8
  - dconf_gnome_screensaver_lock_enabled
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed
  - unknown_strategy

- name: Dconf Update
  command: dconf update
  when:
  - '"gdm" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - ansible_distribution == 'SLES'
  tags:
  - CJIS-5.5.5
  - DISA-STIG-RHEL-07-010060
  - NIST-800-171-3.1.10
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-8.1.8
  - PCI-DSSv4-8.2.8
  - dconf_gnome_screensaver_lock_enabled
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed
  - unknown_strategy

- name: Enable GNOME3 Screensaver Lock After Idle Period
  ini_file:
    dest: /etc/dconf/db/local.d/00-security-settings
    section: org/gnome/desktop/screensaver
    option: lock-enabled
    value: 'true'
    create: true
    no_extra_spaces: true
  when:
  - '"gdm" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - ansible_distribution != 'SLES'
  tags:
  - CJIS-5.5.5
  - DISA-STIG-RHEL-07-010060
  - NIST-800-171-3.1.10
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-8.1.8
  - PCI-DSSv4-8.2.8
  - dconf_gnome_screensaver_lock_enabled
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed
  - unknown_strategy

- name: Prevent user modification of GNOME lock-enabled
  lineinfile:
    path: /etc/dconf/db/local.d/locks/00-security-settings-lock
    regexp: ^/org/gnome/desktop/screensaver/lock-enabled$
    line: /org/gnome/desktop/screensaver/lock-enabled
    create: true
  when:
  - '"gdm" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - ansible_distribution != 'SLES'
  tags:
  - CJIS-5.5.5
  - DISA-STIG-RHEL-07-010060
  - NIST-800-171-3.1.10
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-8.1.8
  - PCI-DSSv4-8.2.8
  - dconf_gnome_screensaver_lock_enabled
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed
  - unknown_strategy

- name: Enable GNOME3 Screensaver Lock After Idle Period
  ini_file:
    dest: /etc/dconf/db/local.d/00-security-settings
    section: org/gnome/desktop/lockdown
    option: disable-lock-screen
    value: 'false'
    create: true
    no_extra_spaces: true
  when:
  - '"gdm" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - ansible_distribution == 'SLES'
  tags:
  - CJIS-5.5.5
  - DISA-STIG-RHEL-07-010060
  - NIST-800-171-3.1.10
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-8.1.8
  - PCI-DSSv4-8.2.8
  - dconf_gnome_screensaver_lock_enabled
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed
  - unknown_strategy

- name: Prevent user modification of GNOME disable-lock-screen
  lineinfile:
    path: /etc/dconf/db/local.d/locks/00-security-settings-lock
    regexp: ^/org/gnome/desktop/lockdown/disable-lock-screen$
    line: /org/gnome/desktop/lockdown/disable-lock-screen
    create: true
  when:
  - '"gdm" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - ansible_distribution == 'SLES'
  tags:
  - CJIS-5.5.5
  - DISA-STIG-RHEL-07-010060
  - NIST-800-171-3.1.10
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-8.1.8
  - PCI-DSSv4-8.2.8
  - dconf_gnome_screensaver_lock_enabled
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed
  - unknown_strategy

- name: Check GNOME3 screenserver disable-lock-screen false
  command: gsettings get org.gnome.desktop.lockdown disable-lock-screen
  register: cmd_out
  when:
  - '"gdm" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - ansible_distribution == 'SLES'
  tags:
  - CJIS-5.5.5
  - DISA-STIG-RHEL-07-010060
  - NIST-800-171-3.1.10
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-8.1.8
  - PCI-DSSv4-8.2.8
  - dconf_gnome_screensaver_lock_enabled
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed
  - unknown_strategy

- name: Update GNOME3 screenserver disable-lock-screen false
  command: gsettings set org.gnome.desktop.lockdown disable-lock-screen false
  when:
  - '"gdm" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - ansible_distribution == 'SLES'
  tags:
  - CJIS-5.5.5
  - DISA-STIG-RHEL-07-010060
  - NIST-800-171-3.1.10
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-8.1.8
  - PCI-DSSv4-8.2.8
  - dconf_gnome_screensaver_lock_enabled
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed
  - unknown_strategy

- name: Dconf Update
  command: dconf update
  when:
  - '"gdm" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.5.5
  - DISA-STIG-RHEL-07-010060
  - NIST-800-171-3.1.10
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-8.1.8
  - PCI-DSSv4-8.2.8
  - dconf_gnome_screensaver_lock_enabled
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed
  - unknown_strategy

# Remediation is applicable only in certain platforms
if rpm --quiet -q gdm && { [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; }; then

# Check for setting in any of the DConf db directories
# If files contain ibus or distro, ignore them.
# The assignment assumes that individual filenames don't contain :readarray -t SETTINGSFILES < <(grep -r "\\[org/gnome/desktop/screensaver\\]" "/etc/dconf/db/" \
                                | grep -v 'distro\|ibus\|local.d' | cut -d":" -f1)
DCONFFILE="/etc/dconf/db/local.d/00-security-settings"
DBDIR="/etc/dconf/db/local.d"

mkdir -p "${DBDIR}"

# Comment out the configurations in databases different from the target one
if [ "${#SETTINGSFILES[@]}" -ne 0 ]
then
    if grep -q "^\\s*lock-enabled\\s*=" "${SETTINGSFILES[@]}"
    then
        
        sed -Ei "s/(^\s*)lock-enabled(\s*=)/#\1lock-enabled\2/g" "${SETTINGSFILES[@]}"
    fi
fi

[ ! -z "${DCONFFILE}" ] && echo "" >> "${DCONFFILE}"
if ! grep -q "\\[org/gnome/desktop/screensaver\\]" "${DCONFFILE}"
then
    printf '%s\n' "[org/gnome/desktop/screensaver]" >> ${DCONFFILE}
fi

escaped_value="$(sed -e 's/\\/\\\\/g' <<< "true")"
if grep -q "^\\s*lock-enabled\\s*=" "${DCONFFILE}"
then
        sed -i "s/\\s*lock-enabled\\s*=\\s*.*/lock-enabled=${escaped_value}/g" "${DCONFFILE}"
    else
        sed -i "\\|\\[org/gnome/desktop/screensaver\\]|a\\lock-enabled=${escaped_value}" "${DCONFFILE}"
fi

dconf update
# Check for setting in any of the DConf db directories
LOCKFILES=$(grep -r "^/org/gnome/desktop/screensaver/lock-enabled$" "/etc/dconf/db/" \
            | grep -v 'distro\|ibus\|local.d' | grep ":" | cut -d":" -f1)
LOCKSFOLDER="/etc/dconf/db/local.d/locks"

mkdir -p "${LOCKSFOLDER}"

# Comment out the configurations in databases different from the target one
if [[ ! -z "${LOCKFILES}" ]]
then
    sed -i -E "s|^/org/gnome/desktop/screensaver/lock-enabled$|#&|" "${LOCKFILES[@]}"
fi

if ! grep -qr "^/org/gnome/desktop/screensaver/lock-enabled$" /etc/dconf/db/local.d/
then
    echo "/org/gnome/desktop/screensaver/lock-enabled" >> "/etc/dconf/db/local.d/locks/00-security-settings-lock"
fi

dconf update

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Enable GNOME3 Screensaver Lock After Idle Period

Description

Rationale

Remediation - Ansible

Remediation - Shell Script