USN-4124-1: Exim vulnerability

6 September 2019

exim4 vulnerability

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

  • Ubuntu 19.04
  • Ubuntu 18.04 LTS
  • Ubuntu 16.04 LTS


Exim could be made to run programs as an administrator if it received specially crafted network traffic.

Software Description

  • exim4 - Exim is a mail transport agent


It was discovered that Exim incorrectly handled certain decoding operations. A remote attacker could possibly use this issue to execute arbitrary commands.

Update instructions

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

Ubuntu 19.04
exim4-daemon-heavy - 4.92-4ubuntu1.3
exim4-daemon-light - 4.92-4ubuntu1.3
Ubuntu 18.04 LTS
exim4-daemon-heavy - 4.90.1-1ubuntu1.4
exim4-daemon-light - 4.90.1-1ubuntu1.4
Ubuntu 16.04 LTS
exim4-daemon-heavy - 4.86.2-2ubuntu2.5
exim4-daemon-light - 4.86.2-2ubuntu2.5

To update your system, please follow these instructions:

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