SV-281343r1167179: RHEL 10 must log Internet Protocol version 4 (IPv4) packets with impossible addresses. | Red Hat Enterprise Linux 10 STIG SCAP Benchmark

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Assessment Title

Rule Text

RHEL 10 must log Internet Protocol version 4 (IPv4) packets with impossible addresses.

Description

Discussion Text

The presence of "martian" packets (which have impossible addresses), as well as spoofed packets, source-routed packets, and redirects, could be a sign of nefarious network activity. Logging these packets enables this activity to be detected. Satisfies: SRG-OS-000420-GPOS-00186, SRG-OS-000142-GPOS-00074

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

IA Controls

NIST SP 800-53

Not mappedCCI-002385Not mappedCCI-001098

References

DPMS Target Red Hat Enterprise Linux 10 DISA DPMS Target Red Hat Enterprise Linux 10 5733

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.rhel10os:def:281343
# RHEL 10 must log Internet Protocol version 4 (IPv4) packets with impossible addresses.
# Per-module read mechanism curated from static teardown of DISA's SCC tool
# (SCAP Compliance Checker) -- see the SCC Automation Reference above.

# net.ipv4.conf.all.log_martians setting in kernel set to 1
# sysctl_object (sysctl_test)
test_1() {
  [ "$(cat /proc/sys/net/ipv4/conf/all/log_martians)" -eq 1 ]
}

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:mil.disa.stig.rhel10os:def:281343

if ! command -v sysctl >/dev/null; then
  echo "FAIL"
  exit 1
fi

if [ ! -f "/etc/sysctl.d/99-ipv4_log_martians.conf" ]; then
  echo "PASS"
  exit 0
fi

if grep -q "^net.ipv4.conf.all.log_martians=1$" /etc/sysctl.d/99-ipv4_log_martians.conf; then
  echo "PASS"
  exit 0
fi

echo "FAIL"
exit 1

Remediation

Configure RHEL 10 to log martian packets on IPv4 interfaces.

Create a configuration file if it does not already exist:

$ sudo vi /etc/sysctl.d/99-ipv4_log_martians.conf

Add the following line to the file:

net.ipv4.conf.all.log_martians=1

Reload settings from all system configuration files with the following command:

$ sudo sysctl --system