Ubuntu Security Notice USN-820-1 – Federico Muttis discovered that Pidgin did not properly handle certain malformed messages in the MSN protocol handler. A remote attacker could send a specially crafted message and possibly execute arbitrary code with user privileges.
You can download this advisory from the following link: https://packetstormsecurity.com/files/download/80511/USN-820-1.txt
Source: https://packetstormsecurity.com/files/80511/Ubuntu-Security-Notice-820-1.html