| name | CIS Ubuntu 14.04 LTS - 6.2.20 Ensure shadow group is empty |
| description | Verify the shadow group has no users assigned to it |
| category | cis-os-hardening |
| version | 2.1.0 |
| author | cyberstrike-official |
| tags | ["cis","ubuntu","ubuntu-14.04","level-1","scored","user-accounts"] |
| cis_id | 6.2.20 |
| cis_benchmark | CIS Ubuntu Linux 14.04 LTS Benchmark v2.1.0 |
| tech_stack | ["ubuntu","linux"] |
| cwe_ids | [] |
| chains_with | [] |
| prerequisites | [] |
| severity_boost | high |
6.2.20 Ensure shadow group is empty (Scored)
Profile Applicability
- Level 1 - Server
- Level 1 - Workstation
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.
Rationale
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.
Audit Procedure
Run the following commands and verify no results are returned:
grep ^shadow:[^:]*:[^:]*:[^:]+ /etc/group
awk -F: '($4 == "<shadow-gid>") { print }' /etc/passwd
Expected Result
No output should be returned.
Remediation
Remove all users from the shadow group, and change the primary group of any users with shadow as their primary group.
Default Value
The shadow group is empty by default.
References
None
CIS Controls
5.1 Minimize And Sparingly Use Administrative Privileges - Minimize administrative privileges and only use administrative accounts when they are required. Implement focused auditing on the use of administrative privileged functions and monitor for anomalous behavior.
Profile
