crontab by Paul Vixie uses predictable file names for a temporary file and does not properly ensure that the file is owned by the user executing the crontab -e command, which allows local users with write access to the crontab spool directory to execute arbitrary commands by creating world-writeable temporary files and modifying them while the victim is editing the file.

Vixie Cron on Linux systems allows local users to set parameters of sendmail commands via the MAILTO environmental variable.

Buffer overflow in Vixie cron allows local users to gain root access via a long MAILTO environment variable in a crontab file.

Buffer overflow in Vixie Cron library up to version 3.0 allows local users to obtain root access via a long environmental variable.