Disable WIFI Network Connection Creation in GNOME3

An XCCDF Rule

Description

GNOME allows users to create ad-hoc wireless connections through the NetworkManager applet. Wireless connections should be disabled by adding or setting disable-wifi-create to true in /etc/dconf/db/local.d/00-security-settings. For example:

[org/gnome/nm-applet]
disable-wifi-create=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/nm-applet/disable-wifi-create

After the settings have been set, run dconf update.

Rationale

Wireless network connections should not be allowed to be configured by general users on a given system as it could open the system to backdoor attacks.

ID: xccdf_org.ssgproject.content_rule_dconf_gnome_disable_wifi_create
Severity: Medium
References: 3.1.16

CCE-86409-0
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/nm-applet\\]" "/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 [ "${#SETTINGSFILES[@]}" -ne 0 ]
then
    if grep -q "^\\s*disable-wifi-create\\s*=" "${SETTINGSFILES[@]}"
    then
        
        sed -Ei "s/(^\s*)disable-wifi-create(\s*=)/#\1disable-wifi-create\2/g" "${SETTINGSFILES[@]}"
    fi
fi

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

escaped_value="$(sed -e 's/\\/\\\\/g' <<< "true")"
if grep -q "^\\s*disable-wifi-create\\s*=" "${DCONFFILE}"
then
        sed -i "s/\\s*disable-wifi-create\\s*=\\s*.*/disable-wifi-create=${escaped_value}/g" "${DCONFFILE}"
    else
        sed -i "\\|\\[org/gnome/nm-applet\\]|a\\disable-wifi-create=${escaped_value}" "${DCONFFILE}"
fi

dconf update
# Check for setting in any of the DConf db directories
LOCKFILES=$(grep -r "^/org/gnome/nm-applet/disable-wifi-create$" "/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 "${LOCKFILES}" ]]
then
    sed -i -E "s|^/org/gnome/nm-applet/disable-wifi-create$|#&|" "${LOCKFILES[@]}"
fi

if ! grep -qr "^/org/gnome/nm-applet/disable-wifi-create$" /etc/dconf/db/local.d/
then
    echo "/org/gnome/nm-applet/disable-wifi-create" >> "/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-86409-0
  - NIST-800-171-3.1.16  - dconf_gnome_disable_wifi_create
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed
  - unknown_strategy

- name: Disable WiFi Network Connection Creation in GNOME3
  ini_file:
    dest: /etc/dconf/db/local.d/00-security-settings
    section: org/gnome/nm-applet
    option: disable-wifi-create
    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-86409-0
  - NIST-800-171-3.1.16
  - dconf_gnome_disable_wifi_create
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed
  - unknown_strategy

- name: Prevent user modification of GNOME3 disablement of WiFi
  lineinfile:
    path: /etc/dconf/db/local.d/locks/00-security-settings-lock
    regexp: ^/org/gnome/nm-applet/disable-wifi-create$
    line: /org/gnome/nm-applet/disable-wifi-create
    create: true
  when:
  - '"gdm" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CCE-86409-0
  - NIST-800-171-3.1.16
  - dconf_gnome_disable_wifi_create
  - 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-86409-0
  - NIST-800-171-3.1.16
  - dconf_gnome_disable_wifi_create
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed
  - unknown_strategy

Disable WIFI Network Connection Creation in GNOME3

Description

Rationale

Remediation - Shell Script

Remediation - Ansible