cron-for-root-only-security
The cron daemon is used to schedule processes. The crontab command is used to create personal crontab entries for users or the root account. To enhance security of the cron scheduler, you can establish the cron.deny and cron.allow files to control use of the crontab. The following commands will establish root as the only user with permission to add cron jobs.
cd /etc/ /bin/rm -f cron.deny at.deny echo root >cron.allow echo root >at.allow /bin/chown root:root cron.allow at.allow /bin/chmod 400 cron.allow at.allow