Assume that a registered user uses a customized endpoint to join an audio or video conference in a Microsoft Lync Server 2010 environment. When the endpoint sends an INVITE request that contains an invalid MIME body to the Audio/Video Conferencing server, the server crashes. Additionally, an unhandled exception is received on the server.
To resolve this issue, install the following cumulative update:
2514978 Description of the cumulative update for Lync Server 2010, Conferencing Server: November 2011