Debian Security Advisory 1121-1 – Peter Bieringer discovered that postgrey, an greylisting implementation for Postfix, is vulnerable to a format string attack that allows remote attackers to the daemon.
You can download this advisory from the following link: https://packetstormsecurity.com/files/download/48553/dsa-1121-1.txt
Source: https://packetstormsecurity.com/files/48553/Debian-Linux-Security-Advisory-1121-1.html