I. BACKGROUND mIRC is "a friendly IRC client that is well equipped with options and tools" More information about the application is available at http://www.mirc.com II. DESCRIPTION The DCC server which is builtin in mirc listens on port 59 if enabled, and is insecure by design. III. ANALYSIS Connecting to the target om port 59 via for example netcat and typing 100 nick-to-spoof will show a dcc chat request in the targets client, appearing to originate from nick-to-spoof. This can be dangerous if trust relationships are observed between a vulnerable user and a user on a multi-user system, be it a shellprovider/vhost supplier or the likes. IV. DETECTION mIRC 6.03 and below (those versions who incorporate the DCC server) are found to be vulnerable. V. WORKAROUND unknown VI. VENDOR FIX unknown VII. CVE INFORMATION unknown VIII. DISCLOSURE TIMELINE unknown IX. CREDIT / Knud Erik Højgaard/kokaninATdtors.net