USN-4294-1: OpenSMTPD vulnerabilities

2 March 2020

OpenSMTPD vulnerabilities

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

  • Ubuntu 19.10
  • Ubuntu 18.04 LTS


Several security issues were fixed in opensmtpd.

Software Description

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


It was discovered that OpenSMTPD mishandled certain input. A remote, unauthenticated attacker could use this vulnerability to execute arbitrary shell commands as any non-root user. (CVE-2020-8794)

It was discovered that OpenSMTPD did not properly handle hardlinks under certain conditions. An unprivileged local attacker could read the first line of any file on the filesystem. (CVE-2020-8793)

Update instructions

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

Ubuntu 19.10
opensmtpd - 6.0.3p1-6ubuntu0.2
Ubuntu 18.04 LTS
opensmtpd - 6.0.3p1-1ubuntu0.2

To update your system, please follow these instructions:

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