Heap-based buffer overflow in the encode_msg function in encode_msg.c in the SEAS module in Kamailio (formerly OpenSER and SER) before 4.3.5 allows remote attackers to cause a denial of service (memory corruption and process crash) or possibly execute arbitrary code via a large SIP packet.
http://www.securityfocus.com/archive/1/537926/100/0/threaded
http://www.kamailio.org/pub/kamailio/4.3.5/ChangeLog