SV-253121r991589: TOSS must not accept router advertisements on all IPv6 interfaces. | Tri-Lab Operating System Stack (TOSS) 4 STIG SCAP Benchmark

Loading benchmark…

Assessment Title

Rule Text

TOSS must not accept router advertisements on all IPv6 interfaces.

Description

Discussion Text

Routing protocol daemons are typically used on routers to exchange network topology information with other routers. If this software is used when not required, system network information may be unnecessarily transmitted across the network. An illicit router advertisement message could result in a man-in-the-middle attack.

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

IA Controls

NIST SP 800-53

Not mappedCCI-000366

References

DPMS Target TOSS 4 DISA DPMS Target TOSS 4 5469

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.toss4os:def:253121
# TOSS must not accept router advertisements on all IPv6 interfaces.
# Per-module read mechanism curated from static teardown of DISA's SCC tool
# (SCAP Compliance Checker) -- see the SCC Automation Reference above.
#
# MANUAL REVIEW REQUIRED -- the module(s) below could not be reconstructed
# into working code from curated SCC reference data, and are excluded from
# the automated result:
#   - textfilecontent54_object (textfilecontent54_test): <set> composition (base object oval:mil.disa.stig.ind:obj:23054100, oval:mil.disa.stig.ind:obj:23054101): member unresolved -- no extractor for field "subexpression"

# sysctl_object (sysctl_test)
test_1() {
  [ "$(cat /proc/sys/net/ipv6/conf/all/accept_ra)" -eq 0 ]
}

if test_1; then
  echo "PASS (automated portion only -- MANUAL REVIEW still required, see notes above)"
else
  echo "FAIL (or see MANUAL REVIEW note above)"
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.toss4os:def:253121
if [ ! -x "/usr/sbin/sysctl" ]; then echo "FAIL"; exit 1; fi
if [ $(sysctl -n net.ipv6.conf.all.accept_ra 2>/dev/null) -eq 0 ]; then echo "PASS"; exit 0; fi
if [ ! -f "/etc/sysctl.d/99-sysctl.conf" ]; then echo "PASS"; exit 0; fi
if grep -q "^net\.ipv6\.conf\.all\.accept_ra=0$" /etc/sysctl.d/99-sysctl.conf; then echo "PASS"; exit 0; fi
if grep -q "^net\.ipv6\.conf\.all\.accept_ra=0$" /etc/sysctl.conf; then echo "PASS"; exit 0; fi
echo "FAIL"; exit 1

Remediation

Configure TOSS to not accept router advertisements on all IPv6 interfaces unless the system is a router with the following commands:

$ sudo sysctl -w net.ipv6.conf.all.accept_ra=0

If "0" is not the system's default value then add or update the following lines in the appropriate file under "/etc/sysctl.d":

net.ipv6.conf.all.accept_ra=0