cyberstrikeus 12.2 Verify Permissions on /etc/shadow (Scored)
Profile Applicability
- Level 1
Description
The /etc/shadow file is used to store the information about user accounts that is critical to the security of those accounts, such as the hashed password and other security information.
Rationale
If attackers can gain read access to the /etc/shadow file, they can easily run a password cracking program against the hashed password to break it. Other security information that is stored in the /etc/shadow file (such as expiration) could also be useful to subvert the user accounts.
Audit Procedure
Using Command Line
Run the following command to determine the permissions on the /etc/shadow file. Ensure world has no access, group has no write or execute access.
/bin/ls -l /etc/shadow
Expected Result
-rw-r----- 1 root shadow <size> <date> shadow
Permissions should be o-rwx,g-rw or more restrictive.
Remediation
Using Command Line
If the permissions of the /etc/shadow file are incorrect, run the following commands to correct them:
/bin/chmod o-rwx,g-rw /etc/shadow
Default Value
640 (rw-r-----)
References
- CIS Ubuntu 12.04 LTS Server Benchmark v1.1.0
Profile
Level 1 - Scored