Information
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.
Solution
Run the following commands to set ownership and permissions on /etc/crontab :
# chown root:root /etc/crontab
# chmod og-rwx /etc/crontab