Ensure shadow group is empty

MediumLevel 1Manual reviewcos

Description

The shadow group allows system programs which require access the ability to read the /etc/shadow file. No users should be assigned to the shadow group. Any users assigned to the shadow group would be granted read access to the /etc/shadow file. If attackers can gain read access to the /etc/shadow file, they can easily run a password cracking program against the hashed passwords to break them. Other security information that is stored in the /etc/shadow file (such as expiration) could also be useful to subvert additional user accounts.

How it is checked

Audit method: Manual review

This recommendation cannot be checked automatically. A scan lists it with these instructions when you pass --include-manual.

Run the following commands and verify no results are returned: # grep ^shadow:[^:]*:[^:]*:[^:]+ /etc/group # awk -F: '($4 == "<shadow-gid>") { print }' /etc/passwd

How it is fixed

Fix method: Guidance or infrastructure patch

Remove all users from the shadow group, and change the primary group of any users with shadow as their primary group.

Properties

Operating systems: Any
Tags: container-optimized-oscos
Reference: CIS Google Container-Optimized OS Benchmark v1.2.0 - 6.2.20 Ensure shadow group is empty