It was discovered that the Dovecot email server is vulnerable to a
denial of service attack against imap/pop3-login processes due to
incorrect handling of the closure of inactive SSL/TLS connections.
For the stable distribution (wheezy), this problem has been fixed in
version 1:2.1.7-7+deb7u1.
For the testing distribution (jessie), this problem has been fixed in
version 1:2.2.13~rc1-1.
For the unstable distribution (sid), this problem has been fixed in
version 1:2.2.13~rc1-1.
We recommend that you upgrade your dovecot packages.