All world-writable directories must be group-owned by root, sys, bin, or an application group.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-75583	UBTU-16-010840	SV-90263r2_rule		Medium

Description
If a world-writable directory has the sticky bit set and is not group-owned by a privileged Group Identifier (GID), unauthorized users may be able to modify files created by others. The only authorized public directories are those temporary directories supplied with the system or those designed to be temporary file repositories. The setting is normally reserved for directories used by the system and by users for temporary file storage, (e.g., /tmp), and for directories requiring global read/write access.

Description

If a world-writable directory has the sticky bit set and is not group-owned by a privileged Group Identifier (GID), unauthorized users may be able to modify files created by others. The only authorized public directories are those temporary directories supplied with the system or those designed to be temporary file repositories. The setting is normally reserved for directories used by the system and by users for temporary file storage, (e.g., /tmp), and for directories requiring global read/write access.

STIG	Date
Canonical Ubuntu 16.04 LTS Security Technical Implementation Guide	2018-07-18

Details

Check Text ( C-75287r2_chk )
Verify all world-writable directories are group-owned by root, sys, bin, or an application group. Check the system for world-writable directories with the following command: # sudo find / -perm -2 -type d ! -group sys ! -group root ! -group bin -exec ls -lLd {} \; drwxrwsrwt 2 root whoops 4096 Jun 6 07:44 /var/crash drwxrwsrwt 2 root whoops 4096 Jul 19 2016 /var/metrics If any world-writable directories are not owned by root, sys, bin, or an application group associated with the directory, this is a finding.

Check Text ( C-75287r2_chk )

Verify all world-writable directories are group-owned by root, sys, bin, or an application group.

Check the system for world-writable directories with the following command:

# sudo find / -perm -2 -type d ! -group sys ! -group root ! -group bin -exec ls -lLd {} \;
drwxrwsrwt 2 root whoops 4096 Jun 6 07:44 /var/crash
drwxrwsrwt 2 root whoops 4096 Jul 19 2016 /var/metrics

If any world-writable directories are not owned by root, sys, bin, or an application group associated with the directory, this is a finding.

Fix Text (F-82211r1_fix)
Change the group of the world-writable directories to root with the following command: # chgrp root