Please Install the Updated Packages.
It was discovered that Dovecot incorrectly handled closing inactive SSL/TLS connections. A remote attacker could use this issue to cause Dovecot to stop responding to new connections, resulting in a denial of service.
dovecot on Ubuntu 14.04 LTS , Ubuntu 13.10 , Ubuntu 12.10 , Ubuntu 12.04 LTS , Ubuntu 10.04 LTS
Updated on 2015-03-25