Cerulean Studios Trillian 0.73 and earlier use weak encrypttion (XOR) for storing user passwords in .ini files in the Trillian directory, which allows local users to gain access to other user accounts.

Buffer overflow in the XML parser of Trillian 0.6351, 0.725 and 0.73 allows remote attackers to cause a denial of service (crash) and possibly execute arbitrary code via a skin with a long colors file name in trillian.xml.

Buffer overflow in the IRC module of Trillian 0.725 and 0.73 allowing remote attackers to execute arbitrary code via a long DCC Chat message.

Buffer overflow in the IDENT daemon (identd) in Trillian 0.6351, 0.725, 0.73, 0.74 and 1.0 pro allows remote attackers to cause a denial of service (crash) and possibly execute arbitrary code via a long request.

Buffer overflow in Trillian 0.73 allows remote IRC servers to execute arbitrary code via a long PING response.

Format string vulnerability in the error handling of IRC invite responses for Trillian 0.725 and 0.73 allows remote IRC servers to execute arbitrary code via an invite to a channel with format string specifiers in the name.

AOL Instant Messenger (AIM) 4.7.2480 and earlier allows remote attackers to cause a denial of service (application crash) via an instant message that contains a large amount of "<!--" HTML comments.