cyberstrikeus 6.2.8 Ensure no duplicate group names exist (Automated)
Profile
- Level 1 - Server
- Level 1 - Workstation
Description
Although the groupadd program will not let you create a duplicate group name, it is possible for an administrator to manually edit the /etc/group file and change the group name.
Rationale
If a group is assigned a duplicate group name, it will create and have access to files with the first GID for that group in /etc/group. Effectively, the GID is shared, which is a security problem.
Audit Procedure
Command Line
Run the following script and verify no results are returned:
#!/usr/bin/env bash
{
while read -r l_count l_group; do
if [ "$l_count" -gt 1 ]; then
echo -e "Duplicate Group: \"$l_group\" Groups: \"$(awk -F: '($1 == n) { print $1 }' n=$l_group /etc/group | xargs)\""
fi
done < <(cut -f1 -d":" /etc/group | sort -n | uniq -c)
}
Expected Result
No output should be returned.
Remediation
Command Line
Based on the results of the audit script, establish unique names for the user groups. File group ownerships will automatically reflect the change as long as the groups have unique GIDs.
References
- NIST SP 800-53 Rev. 5: CM-1, CM-2, CM-6, CM-7, IA-5
CIS Controls
- v8: 5.2 Use Unique Passwords
- v7: 4.4 Use Unique Passwords