Format string vulnerability in the SMTP server component in Qbik WinGate 5.x and 6.x before 6.2.2 allows remote attackers to cause a denial of service (service crash) via format string specifiers in certain unexpected commands, which trigger a crash during error logging.
https://exchange.xforce.ibmcloud.com/vulnerabilities/35950
http://www.wingate.com/news.php?id=50
http://www.vupen.com/english/advisories/2007/2859
http://www.securityfocus.com/bid/25303
http://www.securityfocus.com/bid/25272
http://www.securityfocus.com/archive/1/476011/100/0/threaded
http://www.harmonysecurity.com/HS-A007.html