SV-281355r1167215: RHEL 10 must ignore IPv6 Internet Control Message Protocol (ICMP) redirect messages. | Red Hat Enterprise Linux 10 STIG SCAP Benchmark

Loading benchmark…

Assessment Title

Rule Text

RHEL 10 must ignore IPv6 Internet Control Message Protocol (ICMP) redirect messages.

Description

Discussion Text

An illicit ICMP redirect message could result in a man-in-the-middle attack. Satisfies: SRG-OS-000420-GPOS-00186, SRG-OS-000142-GPOS-00086

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

IA Controls

NIST SP 800-53

Not mappedCCI-002385Not mappedCCI-001110

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:281355
# RHEL 10 must ignore IPv6 Internet Control Message Protocol (ICMP) redirect messages.
# Per-module read mechanism curated from static teardown of DISA's SCC tool
# (SCAP Compliance Checker) -- see the SCC Automation Reference above.

# net.ipv6.conf.all.accept_redirects setting in kernel is 0
# sysctl_object (sysctl_test)
test_1() {
  [ "$(cat /proc/sys/net/ipv6/conf/all/accept_redirects)" -eq 0 ]
}

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
# DISA STIG RHEL 10 must ignore IPv6 ICMP redirect messages (oval:mil.disa.stig.rhel10os:def:281355)

if [ ! -f "/etc/sysctl.d/ipv6_accept_redirects.conf" ]; then
    echo "PASS"
    exit 0
fi

if grep -qE "^net\.ipv6\.conf\.all\.accept_redirects = 0$" /etc/sysctl.d/ipv6_accept_redirects.conf; then
    echo "PASS"
    exit 0
else
    echo "FAIL"
    exit 1
fi

Remediation

Configure RHEL 10 to ignore Internet Protocol version 6 (IPv6) ICMP redirect messages.

Create a configuration file if it does not already exist:

$ sudo vi /etc/sysctl.d/ipv6_accept_redirects.conf

Add the following line to the file:

net.ipv6.conf.all.accept_redirects = 0

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

$ sudo sysctl --system