Secunia Security Advisory – Ubuntu has issued an update for libpng. This fixes some vulnerabilities, which can be exploited by malicious people to disclose potentially sensitive information and cause a DoS (Denial of Service).
You can download this advisory from the following link: https://packetstormsecurity.com/files/download/87436/sa38940.txt
Source: https://packetstormsecurity.com/files/87436/Secunia-Security-Advisory-38940.html