USN-3556-1: Dovecot vulnerability

1 February 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


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

Software Description

  • dovecot - IMAP and POP3 email server


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

To update your system, please follow these instructions:

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