The edit_cmd function in crontab.c in (1) cronie before 1.4.4 and (2) Vixie cron (vixie-cron) allows local users to change the modification times of arbitrary files, and consequently cause a denial of service, via a symlink attack on a temporary file in the /tmp directory.
Vixie Cron before 4.1-r10 on Gentoo Linux is installed with insecure permissions, which allows local users to cause a denial of service (cron failure) by creating hard links, which results in a failed st_nlink check in database.c.
do_command.c in Vixie cron (vixie-cron) 4.1 does not check the return code of a setuid call, which might allow local users to gain root privileges if setuid fails in cases such as PAM failures or resource limits, as originally demonstrated by a program that exceeds the process limits as defined in /etc/security/limits.conf.
crontab in Vixie cron 4.1, when running with the -e option, allows local users to read the cron files of other users by changing the file being edited to a symlink. NOTE: there is insufficient information to know whether this is a duplicate of CVE-2001-0235.
crontab in Vixie cron 3.0.1 and earlier does not properly drop privileges after the failed parsing of a modification operation, which could allow a local attacker to gain additional privileges when an editor is called to correct the error.
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.