It was discovered that CUPS did not properly check the height of TIFF images. If a user or automated system were tricked into opening a crafted TIFF image file, a remote attacker could cause a denial of service or possibly execute arbitrary code with user privileges. In Ubuntu 7.10, 8.04 LTS, and 8.10, attackers would be isolated by the AppArmor CUPS profile.
The problem can be corrected by updating your system to the following package versions:
16 April 2009
A security issue affects these releases of Ubuntu and its derivatives:
It was discovered that CUPS did not properly check the height of TIFF images. If a user or automated system were tricked into opening a crafted TIFF image file, a remote attacker could cause a denial of service or possibly execute arbitrary code with user privileges. In Ubuntu 7.10, 8.04 LTS, and 8.10, attackers would be isolated by the AppArmor CUPS profile.
The problem can be corrected by updating your system to the following package versions:
To update your system, please follow these instructions: https://wiki.ubuntu.com/Security/Upgrades.
In general, a standard system upgrade is sufficient to effect the necessary changes.