cyberstrikeus CIS Ubuntu Linux 18.04 LTS Benchmark v2.2.0 - Control 4.1.2
Profile Applicability
- Level 1 - Server
- Level 1 - Workstation
Description
The /etc/crontab file is used by cron to control its own jobs. The commands in this item make sure that root is the user and group owner of the file and that only the owner can access the file.
Rationale
This file contains information on what system jobs are run by cron. Write access to these files could provide unprivileged users with the ability to elevate their privileges. Read access to these files could provide users with the ability to gain insight on system jobs that run on the system and could provide them a way to gain unauthorized privileged access.
Audit Procedure
Command Line
Run the following command and verify Uid and Gid are both 0/root and Access does not grant permissions to group or other:
stat -c "%a %U %G" /etc/crontab
Expected Result
600 root root
OR more restrictive.
Remediation
Command Line
Run the following commands to set ownership and permissions on /etc/crontab:
chown root:root /etc/crontab
chmod og-rwx /etc/crontab
Default Value
Access: (0600/-rw-------) Uid: ( 0/ root) Gid: ( 0/ root)
References
- NIST SP 800-53 Rev. 5: AC-3, MP-2
CIS Controls
v8 - 3.3 Configure Data Access Control Lists - Configure data access control lists based on a user's need to know. Apply data access control lists, also known as access permissions, to local and remote file systems, databases, and applications.
v7 - 14.6 Protect Information through Access Control Lists - Protect all information stored on systems with file system, network share, claims, application, or database specific access control lists.
Profile Applicability
- Level 1 - Server
- Level 1 - Workstation
Assessment Status
Automated