Ubuntu Security Notice 409-1 – Federico L. Bossi Bonin discovered a Denial of Service vulnerability in ksirc. By sending a special response packet, a malicious IRC server could crash ksirc.
You can download this advisory from the following link: https://packetstormsecurity.com/files/download/53686/USN-409-1.txt
Source: https://packetstormsecurity.com/files/53686/Ubuntu-Security-Notice-409-1.html