Secunia Security Advisory – Ubuntu has issued an update for ruby. 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/51569/sa22624.txt
Source: https://packetstormsecurity.com/files/51569/Secunia-Security-Advisory-22624.html