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.
5bf19020b2a22a23698a50a955f08f0203d3d90d40004e4558016718772bd062
Ubuntu Security Notice 929-1 - It was discovered that irssi did not perform certificate host validation when using SSL connections. An attacker could exploit this to perform a man in the middle attack to view sensitive information or alter encrypted communications. Aurelien Delaitre discovered that irssi could be made to dereference a NULL pointer when a user left the channel. A remote attacker could cause a denial of service via application crash. This update also adds SSLv3 and TLSv1 support, while disabling the old, insecure SSLv2 protocol.
591dd365d779ce5c360c93bf7c0aa20059dc2ce95cebcad97cb333b90ee94e22