Enable GNOME3 Screensaver Idle Activation

An XCCDF Rule

Description

To activate the screensaver in the GNOME3 desktop after a period of inactivity, add or set idle-activation-enabled to true in /etc/dconf/db/local.d/00-security-settings. For example:

[org/gnome/desktop/screensaver]
idle-activation-enabled=true

Once the setting has 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/idle-activation-enabled

After the settings have been set, run dconf update.

Rationale

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, GNOME desktops can be configured to identify when a user's session has idled and take action to initiate the session lock.

Enabling idle activation of the screensaver ensures the screensaver will be activated after the idle delay. Applications requiring continuous, real-time screen display (such as network management products) require the login session does not have administrator rights and the display station is located in a controlled-access area.

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

5.5.5

DSS05.04 DSS05.10 DSS06.10

3.1.10

CCI-000057

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

AC-11(a) CM-6(a)

PR.AC-7

FMT_MOF_EXT.1

Req-8.1.8

8.2.8

SRG-OS-000029-GPOS-00010

CCE-87755-5
Updated: about 1 year ago

# 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 [ "${#SETTINGSFILES[@]}" -ne 0 ]
then
    if grep -q "^\\s*idle-activation-enabled\\s*=" "${SETTINGSFILES[@]}"
    then
        
        sed -Ei "s/(^\s*)idle-activation-enabled(\s*=)/#\1idle-activation-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="$(sed -e 's/\\/\\\\/g' <<< "true")"
if grep -q "^\\s*idle-activation-enabled\\s*=" "${DCONFFILE}"
then
        sed -i "s/\\s*idle-activation-enabled\\s*=\\s*.*/idle-activation-enabled=${escaped_value}/g" "${DCONFFILE}"
    else
        sed -i "\\|\\[org/gnome/desktop/screensaver\\]|a\\idle-activation-enabled=${escaped_value}" "${DCONFFILE}"
fi

dconf update
# Check for setting in any of the DConf db directories
LOCKFILES=$(grep -r "^/org/gnome/desktop/screensaver/idle-activation-enabled$" "/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 "${LOCKFILES}" ]]
then
    sed -i -E "s|^/org/gnome/desktop/screensaver/idle-activation-enabled$|#&|" "${LOCKFILES[@]}"
fi

if ! grep -qr "^/org/gnome/desktop/screensaver/idle-activation-enabled$" /etc/dconf/db/local.d/
then
    echo "/org/gnome/desktop/screensaver/idle-activation-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

- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - CCE-87755-5
  - CJIS-5.5.5  - NIST-800-171-3.1.10
  - NIST-800-53-AC-11(a)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-8.1.8
  - PCI-DSSv4-8.2.8
  - dconf_gnome_screensaver_idle_activation_enabled
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed
  - unknown_strategy

- name: Enable GNOME3 Screensaver Idle Activation
  ini_file:
    dest: /etc/dconf/db/local.d/00-security-settings
    section: org/gnome/desktop/screensaver
    option: idle-activation-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"]
  tags:
  - CCE-87755-5
  - CJIS-5.5.5
  - NIST-800-171-3.1.10
  - NIST-800-53-AC-11(a)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-8.1.8
  - PCI-DSSv4-8.2.8
  - dconf_gnome_screensaver_idle_activation_enabled
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed
  - unknown_strategy

- name: Prevent user modification of GNOME idle-activation-enabled
  lineinfile:
    path: /etc/dconf/db/local.d/locks/00-security-settings-lock
    regexp: ^/org/gnome/desktop/screensaver/idle-activation-enabled$
    line: /org/gnome/desktop/screensaver/idle-activation-enabled
    create: true
  when:
  - '"gdm" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CCE-87755-5
  - CJIS-5.5.5
  - NIST-800-171-3.1.10
  - NIST-800-53-AC-11(a)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-8.1.8
  - PCI-DSSv4-8.2.8
  - dconf_gnome_screensaver_idle_activation_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:
  - CCE-87755-5
  - CJIS-5.5.5
  - NIST-800-171-3.1.10
  - NIST-800-53-AC-11(a)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-8.1.8
  - PCI-DSSv4-8.2.8
  - dconf_gnome_screensaver_idle_activation_enabled
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed
  - unknown_strategy

Enable GNOME3 Screensaver Idle Activation

Description

Rationale

Remediation - Shell Script

Remediation - Ansible