Unspecified vulnerability in the attachment filter in Kerio MailServer before 6.4.1 has unknown impact and remote attack vectors.
https://exchange.xforce.ibmcloud.com/vulnerabilities/35618
http://www.vupen.com/english/advisories/2007/2637
http://www.securitytracker.com/id?1018453
http://www.securityfocus.com/bid/25038
http://www.kerio.com/kms_history.html