Cisco TelePresence Video Communication Server (VCS) Expressway X8.5.2 allows remote attackers to cause a denial of service via invalid variables in an authentication packet, aka Bug ID CSCuv40469.
http://www.securitytracker.com/id/1033281
http://www.securityfocus.com/bid/76351
http://tools.cisco.com/security/center/viewAlert.x?alertId=40444