Title

All shell files must not have extended ACLs. (Cat II impact)

Discussion

Shells with world/group write permissions give the ability to maliciously modify the shell to obtain unauthorized access.

Check Content

If /etc/shells exists, check the permissions of each shell referenced. # cat /etc/shells | xargs -n1 ls -lL Otherwise, check any shells found on the system. # find / -name "*sh" | xargs -n1 ls -lL If the permissions include a "+", the file has an extended ACL, this is a finding.

Fix Text

Remove the extended ACL from the file. # chmod A- [shell]

Additional Identifiers

Rule ID: SV-227697r603266_rule

Vulnerability ID: V-227697

Group Title: SRG-OS-000480

Expert Comments

CCIs tied to check.

Controls tied to check. These are derived from the CCIs shown above.