Secunia Security Advisory – Ubuntu has issued an update for ruby1.9. This fixes a vulnerability, which can potentially 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/73119/sa33185.txt
Source: https://packetstormsecurity.com/files/73119/Secunia-Security-Advisory-33185.html