The SIP implementation in Cisco TelePresence TC Software 4.x and 5.x and TE Software 4.x and 6.0 allows remote attackers to cause a denial of service (device reload) via crafted SIP packets, aka Bug ID CSCuj94651.
http://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20140430-tcte