The problem can be corrected by upgrading the affected package to version 3.6.1-1.1ubuntu1.3 (for Ubuntu 4.10), or 3.6.1-5ubuntu0.1 (for Ubuntu 5.04). After a standard system upgrade you need to restart your CUPS server with
sudo /etc/init.d/cupsys restart
to effect the necessary changes.
Tavis Ormandy discovered a buffer overflow in the TIFF library. A malicious image with an invalid "bits per sample" number could be constructed which, when decoded, would have resulted in execution of arbitrary code with the privileges of the process using the library.
Since this library is used in many applications like "ghostscript" and the "CUPS" printing system, this vulnerability may lead to remotely induced privilege escalation.