Buffer overflow in eStara Softphone 3.0.1.14 through 3.0.1.46 allows remote attackers to execute arbitrary code via a long attribute (aka "a") field in the SDP data of a SIP packet on UDP port 5060.
https://exchange.xforce.ibmcloud.com/vulnerabilities/24090
http://www.vupen.com/english/advisories/2006/0167
http://www.securityfocus.com/archive/1/421596/100/0/threaded