Ubuntu Security Notice USN-800-1 – 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.
You can download this advisory from the following link: https://packetstormsecurity.com/files/download/79140/USN-800-1.txt
Source: https://packetstormsecurity.com/files/79140/Ubuntu-Security-Notice-800-1.html