USN-3795-1: libssh vulnerability

17 October 2018

libssh vulnerability

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

  • Ubuntu 18.04 LTS
  • Ubuntu 16.04 LTS
  • Ubuntu 14.04 LTS


libssh could allow unintended access to network services.

Software Description

  • libssh - A tiny C SSH library


Peter Winter-Smith discovered that libssh incorrectly handled authentication when being used as a server. A remote attacker could use this issue to bypass authentication without any credentials.

Update instructions

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

Ubuntu 18.04 LTS
libssh-4 - 0.8.0~20170825.94fa1e38-1ubuntu0.1
Ubuntu 16.04 LTS
libssh-4 - 0.6.3-4.3ubuntu0.1
Ubuntu 14.04 LTS
libssh-4 - 0.6.1-0ubuntu3.4

To update your system, please follow these instructions:

After a standard system update you need to reboot your computer to make all the necessary changes.