Secunia Security Advisory – Ubuntu has issued an update for ntp. This fixes a vulnerability, which can be exploited by malicious people to conduct spoofing attacks.
You can download this advisory from the following link: https://packetstormsecurity.com/files/download/73933/sa33451.txt
Source: https://packetstormsecurity.com/files/73933/Secunia-Security-Advisory-33451.html