Ubuntu Security Notice 639-1 – Drew Yao discovered that the TIFF library did not correctly validate LZW compressed TIFF images. If a user or automated system were tricked into processing a malicious image, a remote attacker could execute arbitrary code or cause an application linked against libtiff to crash, leading to a denial of service.
You can download this advisory from the following link: https://packetstormsecurity.com/files/download/69567/USN-639-1.txt
Source: https://packetstormsecurity.com/files/69567/Ubuntu-Security-Notice-639-1.html