The STUN implementation in Asterisk 1.4.x before 1.4.8, AsteriskNOW before beta7, Appliance Developer Kit before 0.5.0, and s800i before 1.0.2 allows remote attackers to cause a denial of service (crash) via a crafted STUN length attribute in a STUN packet sent on an RTP port.
https://exchange.xforce.ibmcloud.com/vulnerabilities/35480
http://www.vupen.com/english/advisories/2007/2563
http://www.securitytracker.com/id?1018407
http://www.securityfocus.com/bid/24950