SV-270741r1066712: Ubuntu 24.04 LTS must use strong authenticators in establishing nonlocal maintenance and diagnostic sessions. | Canonical Ubuntu 24.04 LTS STIG SCAP Benchmark

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Assessment Title

Rule Text

Ubuntu 24.04 LTS must use strong authenticators in establishing nonlocal maintenance and diagnostic sessions.

Description

Discussion Text

Nonlocal maintenance and diagnostic activities are those activities conducted by individuals communicating through a network, either an external network (e.g., the internet) or an internal network. Local maintenance and diagnostic activities are those activities carried out by individuals physically present at the information system or information system component and not communicating across a network connection. Typically, strong authentication requires authenticators that are resistant to replay attacks and employ multifactor authentication. Strong authenticators include, for example, PKI where certificates are stored on a token protected by a password, passphrase, or biometric.

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

IA Controls

NIST SP 800-53

Not mappedCCI-000877

References

DPMS Target Canonical Ubuntu 24.04 LTS DISA DPMS Target Canonical Ubuntu 24.04 LTS 5673

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.stig.ubuntu2404os:def:270741
# Ubuntu 24.04 LTS must use strong authenticators in establishing nonlocal maintenance and diagnostic sessions.
# Per-module read mechanism curated from static teardown of DISA's SCC tool
# (SCAP Compliance Checker) -- see the SCC Automation Reference above.

# /etc/ssh/sshd_config or /etc/ssh/sshd_config.d/*:UsePAM == yes
# textfilecontent54_object (textfilecontent54_test)
test_1() {
  ( (sed -En 's/^\s*UsePAM\s+(\w*)/\1/p' '/etc/ssh/sshd_config') | grep -qxF 'yes' ) || ( (grep -rhP --include='*.conf' '^\s*UsePAM\s+(\w*)' '/etc/ssh/sshd_config.d' | sed -En 's/^\s*UsePAM\s+(\w*)/\1/p') | grep -qxF 'yes' )
}

if test_1; 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.stig.ubuntu2404os:def:270741

if [ ! -f /etc/ssh/sshd_config ]; then echo "PASS"; exit 0; fi
if grep -q '^\\s*UsePAM\\s+yes$' /etc/ssh/sshd_config; then echo "PASS"; exit 0; fi
if [ ! -d /etc/ssh/sshd_config.d ]; then echo "PASS"; exit 0; fi
for file in /etc/ssh/sshd_config.d/*.conf; do
    if grep -q '^\\s*UsePAM\\s+yes$' "$file"; then echo "PASS"; exit 0; fi
done
echo "FAIL"; exit 1

Remediation

Configure Ubuntu 24.04 LTS to use strong authentication when establishing nonlocal maintenance and diagnostic sessions.  
 
Add or modify the following line to /etc/ssh/sshd_config: 
 
UsePAM yes