The Vonage Motorola Phone Adapter VT 2142-VD does not properly verify that a SIP INVITE message originated from a legitimate server, which allows remote attackers to send spoofed INVITE messages, as demonstrated by a flood of messages triggering a denial of service, and by phone calls with malicious content.
https://exchange.xforce.ibmcloud.com/vulnerabilities/37420
https://exchange.xforce.ibmcloud.com/vulnerabilities/37416
http://www.sipera.com/index.php?action=resources%2Cthreat_advisory&tid=360
http://www.sipera.com/index.php?action=resources%2Cthreat_advisory&tid=357
http://www.securityfocus.com/bid/26129