How to Deny crontab Access

1. Become superuser.

2. Edit the /etc/cron.d/cron.deny file and 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. Verify the /etc/cron.d/cron.deny file.

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