It was discovered that irssi did not properly check the length of strings when processing WALLOPS messages. If a user connected to an IRC network where an attacker had IRC operator privileges, a remote attacker could cause a denial of service.
The problem can be corrected by updating your system to the following package versions:
13 July 2009
A security issue affects these releases of Ubuntu and its derivatives:
It was discovered that irssi did not properly check the length of strings when processing WALLOPS messages. If a user connected to an IRC network where an attacker had IRC operator privileges, a remote attacker could cause a denial of service.
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 upgrade you need to restart irssi to effect the necessary changes.
Vulmon