Thunderbird could be made to crash or run programs as your login if it opened a specially crafted file.
USN-1367-1 fixed vulnerabilities in libpng. This provides the corresponding update for Thunderbird.
17 February 2012
A security issue affects these releases of Ubuntu and its derivatives:
Thunderbird could be made to crash or run programs as your login if it opened a specially crafted file.
USN-1367-1 fixed vulnerabilities in libpng. This provides the corresponding update for Thunderbird.
Original advisory details:
Jueri Aedla discovered that libpng did not properly verify the size used when allocating memory during chunk decompression. If a user or automated system using libpng were tricked into opening a specially crafted image, an attacker could exploit this to cause a denial of service or execute code with the privileges of the user invoking the program. (CVE-2011-3026)
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.
After a standard system update you need to restart Thunderbird to make all the necessary changes.
Vulmon