libpng could be made to crash or run programs as your login if it opened a specially crafted file.
It was discovered that libpng did not properly verify the embedded profile length of iCCP chunks. An attacker could exploit this to cause a denial of service via application crash. This issue only affected Ubuntu 8.04 LTS. (CVE-2009-5063)
16 February 2012
A security issue affects these releases of Ubuntu and its derivatives:
libpng could be made to crash or run programs as your login if it opened a specially crafted file.
It was discovered that libpng did not properly verify the embedded profile length of iCCP chunks. An attacker could exploit this to cause a denial of service via application crash. This issue only affected Ubuntu 8.04 LTS. (CVE-2009-5063)
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 your session to make all the necessary changes.
Vulmon