cis-ubuntu1604-v200-6-2-12

name	cis-ubuntu1604-v200-6-2-12
description	Ensure root PATH Integrity
category	cis-iam
version	2.0.0
author	cyberstrike-official
tags	["cis","ubuntu","linux","ubuntu-16.04","user-management","maintenance"]
cis_id	6.2.12
cis_benchmark	CIS Ubuntu Linux 16.04 LTS Benchmark v2.0.0
tech_stack	["ubuntu","linux"]
cwe_ids	[]
chains_with	[]
prerequisites	[]
severity_boost	{}

CIS Ubuntu Linux 16.04 LTS Benchmark v2.0.0 - Control 6.2.12

Profile

• Level: 1 - Server
• Level: 1 - Workstation
• Assessment Status: Automated

Description

The root user can execute any command on the system and could be fooled into executing programs unintentionally if the PATH is not set correctly.

Rationale

Including the current working directory (.) or other writable directory in root's executable path makes it likely that an attacker can gain superuser access by forcing an administrator operating as root to execute a Trojan horse program.

Audit Procedure

Command Line

Run the following script and verify no results are returned:

#!/bin/bash
RPCV="$(sudo -Hiu root env | grep '^PATH' | cut -d= -f2)"
echo "$RPCV" | grep -q "::" && echo "root's path contains a empty directory (::)"
echo "$RPCV" | grep -q ":$" && echo "root's path contains a trailing (:)"
for x in $(echo "$RPCV" | tr ":" " "); do
    if [ -d "$x" ]; then
        ls -ldH "$x" | awk '$9 == "." {print "PATH contains current working directory (.)"}
            $3 != "root" {print $9, "is not owned by root"}
            substr($1,6,1) != "-" {print $9, "is group writable"}
            substr($1,9,1) != "-" {print $9, "is world writable"}'