cis-ubuntu1204-v110-2-17

name	cis-ubuntu1204-v110-2-17
description	Set Sticky Bit on All World-Writable Directories
category	cis-os-hardening
version	1.1.0
author	cyberstrike-official
tags	["cis","ubuntu",12.04,"linux","filesystem","sticky-bit","permissions","world-writable"]
cis_id	2.17
cis_benchmark	CIS Ubuntu 12.04 LTS Server Benchmark v1.1.0
tech_stack	["ubuntu","linux"]
cwe_ids	[]
chains_with	[]
prerequisites	[]
severity_boost	{}

2.17 Set Sticky Bit on All World-Writable Directories (Scored)

Profile Applicability

• Level 1

Description

Setting the sticky bit on world writable directories prevents users from deleting or renaming files in that directory that are not owned by them.

Rationale

This feature prevents the ability to delete or rename files in world writable directories (such as /tmp) that are owned by another user.

Audit Procedure

Using Command Line

df --local -P | awk {'if (NR!=1) print $6'} | xargs -I '{}' find '{}' -xdev -type d \( -perm -0002 -a ! -perm -1000 \) 2>/dev/null

Expected Result

No output should be returned. If any directories are listed, the sticky bit is not set on them.

Remediation

Using Command Line

df --local -P | awk {'if (NR!=1) print $6'} | xargs -I '{}' find '{}' -xdev -type d -perm -0002 2>/dev/null | xargs chmod a+t

Default Value

By default, the sticky bit is set on /tmp but may not be set on other world-writable directories.

References

• CIS Ubuntu 12.04 LTS Server Benchmark v1.1.0

Profile

Level 1 - Scored