cis-ubuntu2004-v300-3-1-1

name	cis-ubuntu2004-v300-3-1-1
description	Ensure IPv6 status is identified
category	cis-networking
version	3.0.0
author	cyberstrike-official
tags	["cis","ubuntu","linux","ubuntu-20.04","network"]
cis_id	3.1.1
cis_benchmark	CIS Ubuntu Linux 20.04 LTS Benchmark v3.0.0
tech_stack	["ubuntu","linux"]
cwe_ids	[]
chains_with	[]
prerequisites	[]
severity_boost	{}

3.1.1 Ensure IPv6 status is identified (Manual)

Profile

• Level 1 - Server
• Level 1 - Workstation

Description

Internet Protocol Version 6 (IPv6) is the most recent version of Internet Protocol (IP). It's designed to supply IP addressing and additional security to support the predicted growth of connected devices. IPv6 is based on 128-bit addressing and can support 340 undecillion, which is 340,282,366,920,938,463,463,374,607,431,768,211,456 unique addresses.

Features of IPv6:

• Hierarchical addressing and routing infrastructure
• Statefull and Stateless configuration
• Support for quality of service (QoS)
• An ideal protocol for neighboring node interaction

Rationale

IETF RFC 4038 recommends that applications are built with an assumption of dual stack. It is recommended that IPv6 be enabled and configured in accordance with Benchmark recommendations.

• IF - dual stack and IPv6 are not used in your environment, IPv6 may be disabled to reduce the attack surface of the system, and recommendations pertaining to IPv6 can be skipped.

Note: It is recommended that IPv6 be enabled and configured unless this is against local site policy

Impact

IETF RFC 4038 recommends that applications are built with an assumption of dual stack.

When enabled, IPv6 will require additional configuration to reduce risk to the system.

Audit Procedure

Command Line

Run the following script to identify if IPv6 is enabled on the system:

#!/usr/bin/env bash

{
  l_output=""
  ! grep -Pqs -- '^\h*0\b' /sys/module/ipv6/parameters/disable && l_output="- IPv6 is not enabled"
  if sysctl net.ipv6.conf.all.disable_ipv6 | grep -Pqs -- "^\h*net\.ipv6\.conf\.all\.disable_ipv6\h*=\h*1\b" \
&& \
      sysctl net.ipv6.conf.default.disable_ipv6 | grep -Pqs -- \
"^\h*net\.ipv6\.conf\.default\.disable_ipv6\h*=\h*1\b"; then
      l_output="- IPv6 is not enabled"
  fi
  [ -z "$l_output" ] && l_output="- IPv6 is enabled"
  echo -e "\n$l_output\n"
}