How to Deny crontab Access

1. Become superuser.

2. Using the editor of your choice, edit the /etc/cron.d/cron.deny file to add user names, one per line, who will be prevented from using crontab commands.

   daemon bin smtp nuucp listen nobody noaccess username1 username2 username3 . . .

3. Exit the file, saving the changes.

4. Verify the /etc/cron.d/cron.deny file.

   # cat /etc/cron.d/cron.deny