Display the Standard Mandatory DoD Notice and Consent Banner until Explicit Acknowledgement

An XCCDF Rule

Description

Display of a standardized and approved use notification before granting access to the SUSE operating system ensures privacy and security notification verbiage used is consistent with applicable federal laws, Executive Orders, directives, policies, regulations, standards, and guidance.

The banner must be acknowledged by the user prior to allowing the user access to the SUSE operating system. This provides assurance that the user has seen the message and accepted the conditions for access. If the consent banner is not acknowledged by the user, DoD will not be in compliance with system use notifications required by law.

System use notifications are required only for access via logon interfaces with human users and are not required when such human interfaces do not exist.

The banner must be formatted in accordance with applicable DoD policy. Use the following verbiage for the SUSE operating system:

You are accessing a U.S. Government (USG) Information System (IS) that is provided for USG-authorized use only.

By using this IS (which includes any device attached to this IS), you consent to the following conditions:

-The USG routinely intercepts and monitors communications on this IS for purposes including, but not limited to, penetration testing, COMSEC monitoring, network operations and defense, personnel misconduct (PM), law enforcement (LE), and counterintelligence (CI) investigations.

-At any time, the USG may inspect and seize data stored on this IS.

-Communications using, or data stored on, this IS are not private, are subject to routine monitoring, interception, and search, and may be disclosed or used for any USG-authorized purpose.

-This IS includes security measures (e.g., authentication and access controls) to protect USG interests--not for your personal benefit or privacy.

-Notwithstanding the above, using this IS does not constitute consent to PM, LE or CI investigative searching or monitoring of the content of privileged communications, or work product, related to personal representation or services by attorneys, psychotherapists, or clergy, and their assistants. Such communications and work product are private and confidential. See User Agreement for details.

Check the configuration by running the following command:

# more /etc/gdm/Xsession

The beginning of the file must contain the following text immediately after #!/bin/sh:

if ! zenity --text-info \
--title "Consent" \
--filename=/etc/gdm/banner \
--no-markup \
--checkbox="Accept." 10 10; then
sleep 1;
exit 1;
fi

Rationale

Display of a standardized and approved use notification before granting access to the operating system ensures privacy and security notification verbiage used is consistent with applicable federal laws, Executive Orders, directives, policies, regulations, standards, and guidance.

For U.S. Government systems, system use notifications are required only for access via login interfaces with human users and are not required when such human interfaces do not exist.

ID: xccdf_org.ssgproject.content_rule_gui_login_dod_acknowledgement
Severity: Medium
References: CCI-000048 CCI-000050

AC-8 a AC-8 b AC-8.1 (ii) AC-8.1 (iii)

SRG-OS-000023-GPOS-00006

SLES-12-010020

SV-217103r603262_rule

CCE-83003-4
Updated: about 1 year ago

- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - CCE-83003-4
  - DISA-STIG-SLES-12-010020  - NIST-800-53-AC-8 a
  - NIST-800-53-AC-8 b
  - NIST-800-53-AC-8.1 (ii)
  - NIST-800-53-AC-8.1 (iii)
  - gui_login_dod_acknowledgement
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed
  - unknown_strategy

- name: Validate /etc/gdm/Xsession is executable
  stat:
    path: /etc/gdm/Xsession
  register: file_stat
  when: '"gdm" in ansible_facts.packages'
  tags:
  - CCE-83003-4
  - DISA-STIG-SLES-12-010020
  - NIST-800-53-AC-8 a
  - NIST-800-53-AC-8 b
  - NIST-800-53-AC-8.1 (ii)
  - NIST-800-53-AC-8.1 (iii)
  - gui_login_dod_acknowledgement
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed
  - unknown_strategy

- name: Validate /etc/gdm/Xsession is a shell script
  lineinfile:
    dest: /etc/gdm/Xsession
    line: '#!/bin/sh'
  check_mode: true
  register: presence
  when: '"gdm" in ansible_facts.packages'
  tags:
  - CCE-83003-4
  - DISA-STIG-SLES-12-010020
  - NIST-800-53-AC-8 a
  - NIST-800-53-AC-8 b
  - NIST-800-53-AC-8.1 (ii)
  - NIST-800-53-AC-8.1 (iii)
  - gui_login_dod_acknowledgement
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed
  - unknown_strategy

- name: Update file /etc/gdm/Xsession
  blockinfile:
    path: /etc/gdm/Xsession
    block: |
      if ! zenity --text-info \
       --title "Consent" \
       --filename=/etc/gdm/banner \
       --no-markup \
       --checkbox="Accept." 10 10; then
        sleep 1;
        exit 1;
      fi
    insertafter: '#!/bin/sh'
    state: present
  when:
  - '"gdm" in ansible_facts.packages'
  - not presence.changed | bool
  - file_stat.stat.executable | bool
  tags:
  - CCE-83003-4
  - DISA-STIG-SLES-12-010020
  - NIST-800-53-AC-8 a
  - NIST-800-53-AC-8 b
  - NIST-800-53-AC-8.1 (ii)
  - NIST-800-53-AC-8.1 (iii)
  - gui_login_dod_acknowledgement
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed
  - unknown_strategy

# Remediation is applicable only in certain platforms
if rpm --quiet -q gdm; then

if ! [ -x /etc/gdm/Xsession ] ; then
    echo "can only remediate if /etc/gdm/Xsession is an executable shell script" >&2
    exit 1fi

if ! awk 'NR==1 && $0 == "#!/bin/sh" { exit 0 } ; { exit 1 }' /etc/gdm/Xsession ; then
    echo "can only remediate if /etc/gdm/Xsession is a shell script" >&2
    exit 1
fi

f=$(mktemp)

echo '#!/bin/sh

if ! zenity --text-info \
 --title "Consent" \
 --filename=/etc/gdm/banner \
 --no-markup \
 --checkbox="Accept." 10 10; then
  sleep 1;
  exit 1;
fi
' > "$f"

# copy original contents of /etc/gdm/Xsession - but skip the shebang
tail -n +2 /etc/gdm/Xsession >> "$f"

chown --reference=/etc/gdm/Xsession "$f"
chmod --reference=/etc/gdm/Xsession "$f"
mv "$f" /etc/gdm/Xsession

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

Display the Standard Mandatory DoD Notice and Consent Banner until Explicit Acknowledgement

Description

Rationale

Remediation - Ansible

Remediation - Shell Script