==========================================================================
Ubuntu Security Notice USN-3556-1
February 01, 2018

dovecot vulnerability
==========================================================================

A security issue affects these releases of Ubuntu and its derivatives:

- Ubuntu 17.10
- Ubuntu 16.04 LTS
- Ubuntu 14.04 LTS

Summary:

Dovecot could be made to crash if it received specially crafted input.

Software Description:
- dovecot: IMAP and POP3 email server

Details:

It was discovered that Dovecot incorrectly handled certain
authentications. An attacker could possibly use this to cause a denial
of service.

Update instructions:

The problem can be corrected by updating your system to the following
package versions:

Ubuntu 17.10:
  dovecot-core                    1:2.2.27-3ubuntu1.2

Ubuntu 16.04 LTS:
  dovecot-core                    1:2.2.22-1ubuntu2.6

Ubuntu 14.04 LTS:
  dovecot-core                    1:2.2.9-1ubuntu2.3

In general, a standard system update will make all the necessary
changes.

References:
  https://www.ubuntu.com/usn/usn-3556-1
  CVE-2017-15132

Package Information:
  https://launchpad.net/ubuntu/+source/dovecot/1:2.2.27-3ubuntu1.2
  https://launchpad.net/ubuntu/+source/dovecot/1:2.2.22-1ubuntu2.6
  https://launchpad.net/ubuntu/+source/dovecot/1:2.2.9-1ubuntu2.3