Modify the System Login Banner

An XCCDF Rule

Description

To configure the system login banner edit /etc/issue. Replace the default text with a message compliant with the local site policy or a legal disclaimer. The DoD required text is either:

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.

OR:

I've read & consent to terms in IS user agreem't.

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.

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_banner_etc_issue
Severity: Medium
References: 1 12 15 16

DSS05.04 DSS05.10 DSS06.10

3.1.9

CCI-000048 CCI-001384 CCI-001385 CCI-001386 CCI-001387 CCI-001388

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-8(a) AC-8(c)

PR.AC-7

SRG-OS-000023-GPOS-00006 SRG-OS-000228-GPOS-00088

SLES-15-010020

1.8.1.2

CCE-83262-6

SV-234803r958390_rule
Updated: 3 months ago

Remediation Templates

# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default; then
login_banner_text='<xccdf-1.2:sub xmlns:xccdf-1.2="http://checklists.nist.gov/xccdf/1.2" idref="xccdf_org.ssgproject.content_value_login_banner_text" use="legacy"/>'


# Multiple regexes transform the banner regex into a usable banner# 0 - Remove anchors around the banner text
login_banner_text=$(echo "$login_banner_text" | sed 's/^\^\(.*\)\$$/\1/g')
# 1 - Keep only the first banners if there are multiple
#    (dod_banners contains the long and short banner)
login_banner_text=$(echo "$login_banner_text" | sed 's/^(\(.*\.\)|.*)$/\1/g')
# 2 - Add spaces ' '. (Transforms regex for "space or newline" into a " ")
login_banner_text=$(echo "$login_banner_text" | sed 's/\[\\s\\n\]+/ /g')
# 3 - Adds newlines. (Transforms "(?:\[\\n\]+|(?:\\n)+)" into "\n")
login_banner_text=$(echo "$login_banner_text" | sed 's/(?:\[\\n\]+|(?:\\\\n)+)/\n/g')
# 4 - Remove any leftover backslash. (From any parethesis in the banner, for example).
login_banner_text=$(echo "$login_banner_text" | sed 's/\\//g')
formatted=$(echo "$login_banner_text" | fold -sw 80)
zypper install -y "issue-generator"
cat <<EOF >/etc/issue.d/99-oscap-setting
$formatted
EOF
/usr/bin/systemctl enable "issue-generator"
/usr/bin/systemctl start "issue-generator"
# The service may not be running because it has been started and failed,
# so let's reset the state so OVAL checks pass.
# Service should be 'inactive', not 'failed' after reboot though.
if /usr/bin/systemctl --failed | grep -q "issue-generator"; then
    /usr/bin/systemctl reset-failed "issue-generator"
fi

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

- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - CCE-83262-6
  - DISA-STIG-SLES-15-010020  - NIST-800-171-3.1.9
  - NIST-800-53-AC-8(a)
  - NIST-800-53-AC-8(c)
  - banner_etc_issue
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed
  - unknown_strategy
- name: XCCDF Value login_banner_text # promote to variable
  set_fact:
    login_banner_text: !!str <xccdf-1.2:sub xmlns:xccdf-1.2="http://checklists.nist.gov/xccdf/1.2" idref="xccdf_org.ssgproject.content_value_login_banner_text" use="legacy"/>
  tags:
    - always
- name: Modify the System Login Banner Ensure issue-generator is Installed
  package:
    name: issue-generator
    state: present
  when: '"kernel-default" in ansible_facts.packages'
  tags:
  - CCE-83262-6
  - DISA-STIG-SLES-15-010020
  - NIST-800-171-3.1.9
  - NIST-800-53-AC-8(a)
  - NIST-800-53-AC-8(c)
  - banner_etc_issue
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed
  - unknown_strategy

- name: Modify the System Login Banner - Ensure Correct Banner
  copy:
    dest: /etc/issue.d/99-oscap-setting
    content: '{{ login_banner_text | regex_replace("^\^(.*)\$$", "\1") | regex_replace("^\((.*\.)\|.*\)$",
      "\1") | regex_replace("\[\\s\\n\]\+"," ") | regex_replace("\(\?:\[\\n\]\+\|\(\?:\\\\n\)\+\)",
      "\n") | regex_replace("\\", "") | wordwrap() }}'
  when: '"kernel-default" in ansible_facts.packages'
  tags:
  - CCE-83262-6
  - DISA-STIG-SLES-15-010020
  - NIST-800-171-3.1.9
  - NIST-800-53-AC-8(a)
  - NIST-800-53-AC-8(c)
  - banner_etc_issue
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed
  - unknown_strategy

- name: Modify the System Login Banner Retart issue-generator Service on Issue Configration
    Change
  ansible.builtin.systemd:
    name: issue-generator
    enabled: 'yes'
    state: restarted
    masked: 'no'
  when: '"kernel-default" in ansible_facts.packages'
  tags:
  - CCE-83262-6
  - DISA-STIG-SLES-15-010020
  - NIST-800-171-3.1.9
  - NIST-800-53-AC-8(a)
  - NIST-800-53-AC-8(c)
  - banner_etc_issue
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed
  - unknown_strategy

Modify the System Login Banner

Description

Rationale

Remediation Templates

A Shell Script

An Ansible Snippet