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.
git.fedorahosted.org/git/cronie.git?p=cronie.git%3Ba=commit%3Bh=9e4a8fa5f9171fb724981f53879c9b20264aeb61
lists.fedoraproject.org/pipermail/package-announce/2010-February/035762.html
secunia.com/advisories/38700
secunia.com/advisories/38741
secunia.com/advisories/48104
www.securityfocus.com/bid/38391
bugzilla.redhat.com/show_bug.cgi?id=565809