USN-4110-1 introduced a regression in Dovecot.
USN-4110-1 fixed a vulnerability in Dovecot. The update introduced a regression causing a wrong check. This update fixes the problem for Ubuntu 12.04 ESM and Ubuntu 14.04 ESM.
28 August 2019
A security issue affects these releases of Ubuntu and its derivatives:
USN-4110-1 introduced a regression in Dovecot.
USN-4110-1 fixed a vulnerability in Dovecot. The update introduced a regression causing a wrong check. This update fixes the problem for Ubuntu 12.04 ESM and Ubuntu 14.04 ESM.
We apologize for the inconvenience.
Original advisory details:
Nick Roessler and Rafi Rubin discovered that Dovecot incorrectly handled certain data. An attacker could possibly use this issue to cause a denial of service or execute arbitrary code.
The problem can be corrected by updating your system to the following package versions:
To update your system, please follow these instructions: https://wiki.ubuntu.com/Security/Upgrades.
In general, a standard system update will make all the necessary changes.