=========================================================================Ubuntu Security Notice USN-3961-1
April 30, 2019

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

- Ubuntu 19.04
- Ubuntu 18.10

Summary:

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

Software Description:
- dovecot: IMAP and POP3 email server

Details:

It was discovered that the Dovecot Submission login service incorrectly
handled certain operations. A remote attacker could possibly use this issue
to cause Dovecot to crash, resulting in a denial of service.

Update instructions:

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

Ubuntu 19.04:
  dovecot-core                    1:2.3.4.1-1ubuntu2.2
  dovecot-submissiond             1:2.3.4.1-1ubuntu2.2

Ubuntu 18.10:
  dovecot-core                    1:2.3.2.1-1ubuntu3.4
  dovecot-submissiond             1:2.3.2.1-1ubuntu3.4

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

References:
  https://ubuntu.com/security/notices/USN-3961-1
  CVE-2019-11494, CVE-2019-11499

Package Information:
  https://launchpad.net/ubuntu/+source/dovecot/1:2.3.4.1-1ubuntu2.2
  https://launchpad.net/ubuntu/+source/dovecot/1:2.3.2.1-1ubuntu3.4