Kerio MailServer before 6.1.3 Patch 1 allows remote attackers to cause a denial of service (application crash) via a crafted IMAP LOGIN command.
https://exchange.xforce.ibmcloud.com/vulnerabilities/25150
http://www.vupen.com/english/advisories/2006/0898
http://www.securityfocus.com/bid/17043
http://www.securityfocus.com/archive/1/427471/100/0/threaded
http://www.kerio.com/kms_history.html