Mandriva Linux Security Advisory 2010-079 – Irssi before 0.8.15, when SSL is used, does not verify that the server hostname matches a domain name in the subject’s Common Name (CN) field or a Subject Alternative Name field of the X.509 certificate, which allows man-in-the-middle attackers to spoof IRC servers via an arbitrary certificate. core/nicklist.c in Irssi before 0.8.15 allows remote attackers to cause a denial of service (NULL pointer dereference and application crash) via vectors related to an attempted fuzzy nick match at the instant that a victim leaves a channel. Additionally the updated packages disables the SSLv2 protocol and enables the SSLv3 and TLSv1 protocols for added security. The updated packages have been patched to correct these issues.
You can download this advisory from the following link: https://packetstormsecurity.com/files/download/88629/MDVSA-2010-079.txt
Source: https://packetstormsecurity.com/files/88629/Mandriva-Linux-Security-Advisory-2010-079.html