Dovecot 1.1 before 2.2.13 and dovecot-ee before 2.1.7.7 and 2.2.x before 2.2.12.12 does not properly close old connections, which allows remote attackers to cause a denial of service (resource consumption) via an incomplete SSL/TLS handshake for an IMAP/POP3 connection.
http://www.ubuntu.com/usn/USN-2213-1
http://www.securityfocus.com/bid/67306
http://www.openwall.com/lists/oss-security/2014/05/09/8
http://www.openwall.com/lists/oss-security/2014/05/09/4
http://www.mandriva.com/security/advisories?name=MDVSA-2015:113
http://www.debian.org/security/2014/dsa-2954
http://secunia.com/advisories/59552
http://secunia.com/advisories/59537
http://secunia.com/advisories/59051
http://rhn.redhat.com/errata/RHSA-2014-0790.html
http://permalink.gmane.org/gmane.mail.imap.dovecot/77499
http://linux.oracle.com/errata/ELSA-2014-0790.html
http://dovecot.org/pipermail/dovecot-news/2014-May/000273.html