USN-4268-1: OpenSMTPD vulnerability

5 February 2020

OpenSMTPD vulnerability

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

  • Ubuntu 19.10
  • Ubuntu 18.04 LTS


OpenSMTPD could be made to run programs as root if it received specially crafted input over the network.

Software Description

  • opensmtpd - secure, reliable, lean, and easy-to configure SMTP server


It was discovered that OpenSMTPD incorrectly verified the sender’s or receiver’s e-mail addresses under certain conditions. An attacker could use this vulnerability to execute arbitrary commands as root.

Update instructions

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

Ubuntu 19.10
opensmtpd - 6.0.3p1-6ubuntu0.1
Ubuntu 18.04 LTS
opensmtpd - 6.0.3p1-1ubuntu0.1

To update your system, please follow these instructions:

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