The Content Scanner Server in F-Secure Anti-Virus for Microsoft Exchange 6.21 and earlier, F-Secure Anti-Virus for Microsoft Exchange 6.01 and earlier, and F-Secure Internet Gatekeeper 6.32 and earlier allow remote attackers to cause a denial of service (service crash due to unhandled exception) via a certain malformed packet.
https://exchange.xforce.ibmcloud.com/vulnerabilities/17307
http://www.securityfocus.com/bid/11145
http://www.idefense.com/application/poi/display?id=137&type=vulnerabilities