Secunia Security Advisory – Debian has issued an update for proftpd. This fixes a vulnerability, which can be exploited by malicious people to cause a DoS (Denial of Service).
You can download this advisory from the following link: https://packetstormsecurity.com/files/download/52462/sa23069.txt
Source: https://packetstormsecurity.com/files/52462/Secunia-Security-Advisory-23069.html

