Asterisk Project Security Advisory – The Asterisk STUN implementation in the RTP stack has a remotely exploitable crash vulnerability. A pointer may run past accessible memory if Asterisk receives a specially crafted STUN packet on an active RTP port. The code that parses the incoming STUN packets incorrectly checks that the length indicated in the STUN attribute and the size of the STUN attribute header does not exceed the available data. This will cause the data pointer to run past accessible memory and when accessed will cause a crash.
You can download this advisory from the following link: https://packetstormsecurity.com/files/download/57819/ASA-2007-017.txt
Source: https://packetstormsecurity.com/files/57819/ASA-2007-017.txt.html