SV-37915r3: The SSH daemon must be configured with the Department of Defense (DoD) logon banner. | Red Hat Enterprise Linux 5 Security Technical Implementation Guide

Loading benchmark…

Assessment Title

Rule Text

The SSH daemon must be configured with the Department of Defense (DoD) logon banner.

Description

Discussion Text

Failure to display the DoD logon banner prior to a logon attempt will negate legal proceedings resulting from unauthorized access to system resources. The SSH service must be configured to display the DoD logon warning banner either through the SSH configuration or a wrapper program such as TCP_WRAPPERS. The SSH daemon may also be used to provide SFTP service. The warning banner configuration for SSH will apply to SFTP.

How this relates to the STIG checklist: STIG vs SCAP benchmark.

IA Controls

NIST SP 800-53

Not mappedCCI-000048CCE-4431-3

Additional Details

Responsibility

System Administrator

References

DPMS Target Red Hat 5 DISA DPMS Target Red Hat 5 2154

SCC Automation Reference

The reconstructed evaluation script behind this rule's OVAL check(s) — every module a compound check combines, with this rule's own concrete values and DISA's SCC tool's real per-module mechanism curated from static teardown of SCC releases.

#!/bin/bash
# Reconstructed from oval:mil.disa.fso.rhel11:def:361
# The SSH daemon must be configured with the Department of Defense (DoD) logon banner.
# Per-module read mechanism curated from static teardown of DISA's SCC tool
# (SCAP Compliance Checker) -- see the SCC Automation Reference above.

# Conditions are satisfied with the filepath defined for banner in /etc/ssh/sshd_config
# textfilecontent54_object (textfilecontent54_test)
test_1() {
  grep -P '(^\s*You\s+are\s+accessing\s+a\s+U\.S\.\s+Government\s+\(USG\)\s+Information\s+System\s+\(IS\)\s+that\s+is\s+provided\s+for\s+USG[-]authorized\s+use\s+only\.\s+By\s+using\s+this\s+IS\s+\(which\s+includes\s+any\s+device\s+attached\s+to\s+this\s+IS\),\s+you\s+consent\s+to\s+the\s+following\s+conditions:\s+[-]+\s*The\s+USG\s+routinely\s+intercepts\s+and\s+monitors\s+communications\s+on\s+this\s+IS\s+for\s+purposes\s+including,\s+but\s+not\s+limited\s+to,\s+penetration\s+testing,\s+COMSEC\s+monitoring,\s+network\s+operations\s+and\s+defense,\s+personnel\s+misconduct\s+\(PM\),\s+law\s+enforcement\s+\(LE\),\s+and\s+counterintelligence\s+\(CI\)\s+investigations\.\s+[-]+\s*At\s+any\s+time,\s+the\s+USG\s+may\s+inspect\s+and\s+seize\s+data\s+stored\s+on\s+this\s+IS\.\s+[-]+\s*Communications\s+using,\s+or\s+data\s+stored\s+on,\s+this\s+IS\s+are\s+not\s+private,\s+are\s+subject\s+to\s+routine\s+monitoring,\s+interception,\s+and\s+search,\s+and\s+may\s+be\s+disclosed\s+or\s+used\s+for\s+any\s+USG[-]authorized\s+purpose\.\s+[-]+\s*This\s+IS\s+includes\s+security\s+measures\s+\(e\.g\.,\s+authentication\s+and\s+access\s+controls\)\s+to\s+protect\s+USG\s+interests[-]+\s*[-]+\s*not\s+for\s+your\s+personal\s+benefit\s+or\s+privacy\.\s+[-]+\s*Notwithstanding\s+the\s+above,\s+using\s+this\s+IS\s+does\s+not\s+constitute\s+consent\s+to\s+PM,\s+LE\s+or\s+CI\s+investigative\s+searching\s+or\s+monitoring\s+of\s+the\s+content\s+of\s+privileged\s+communications,\s+or work product,\s+related\s+to\s+personal\s+representation\s+or\s+services\s+by\s+attorneys,\s+psychotherapists,\s+or\s+clergy,\s+and\s+their\s+assistants\.\s+Such\s+communications\s+and\s+work\s+product\s+are\s+private\s+and\s+confidential\.\s+See\s+User\s+Agreement\s+for\s+details\.|I've\s+read\s+&\s+consent\s+to\s+terms\s+in\s+IS\s+user\s+agreem't\.)'  &>/dev/null
}
# Banner is defined in /etc/ssh/sshd_config
# textfilecontent54_object (textfilecontent54_test)
test_2() {
  grep -Pq '^\s*[Bb][Aa][Nn][Nn][Ee][Rr]\s+(\S+)\s*$' '/etc/ssh/sshd_config' &>/dev/null
}

if ! ( test_1 && test_2 ); then
  echo "PASS"
else
  echo "FAIL"
fi

Assessment Script Powered by AISandbox-executed

A standalone Shell script to assess this control automatically. Review before running it in your environment.

Syntax-checked and actually executed in an isolated sandbox (not the real system this checks) — confirmed to run without errors.

#!/bin/sh
# OVAL definition: oval:mil.disa.fso.rhel11:def:361

if [ ! -f "/etc/issue" ] || ! grep -q "^You are accessing a U\.S\. Government \(USG\) Information System \(IS\) that is provided for USG-authorized use only\.$" "/etc/issue"; then
    echo "FAIL"
    exit 1
fi

if [ ! -f "/etc/ssh/sshd_config" ] || ! grep -q "^Banner /etc/issue$" "/etc/ssh/sshd_config"; then
    echo "FAIL"
    exit 1
fi

echo "PASS"
exit 0

Remediation

Edit /etc/issue and the DoD login banner.

DoD Login Banners:

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.

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

Find the location of the banner file for sshd and examine the content:

# grep -i banner /etc/ssh/sshd_config | grep -v '^#'
# cat

Edit the SSH daemon configuration and add or edit a "Banner" setting referencing a file containing a logon warning banner.

Restart the SSH daemon.
# /sbin/service sshd restart