Unspecified vulnerability in the SIP module in InGate Firewall and SIParator before 4.5.1 allows remote attackers to conduct replay attacks on the authentication mechanism via unknown vectors.
https://exchange.xforce.ibmcloud.com/vulnerabilities/31546
http://www.vupen.com/english/advisories/2007/0209
http://www.securityfocus.com/bid/22080
http://www.ingate.com/relnote-451.php