USN-3795-3: libssh regression

29 November 2018

libssh regression

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

  • Ubuntu 18.10
  • Ubuntu 18.04 LTS
  • Ubuntu 16.04 LTS
  • Ubuntu 14.04 LTS


USN-3795-1 and USN-3795-2 introduced a regression in libssh.

Software Description

  • libssh - A tiny C SSH library


USN-3795-1 and USN-3795-2 fixed a vulnerability in libssh. The upstream fix introduced a regression. This update fixes the problem.

Original advisory details:

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 18.10
libssh-4 - 0.8.1-1ubuntu0.3
Ubuntu 18.04 LTS
libssh-4 - 0.8.0~20170825.94fa1e38-1ubuntu0.2
Ubuntu 16.04 LTS
libssh-4 - 0.6.3-4.3ubuntu0.2
Ubuntu 14.04 LTS
libssh-4 - 0.6.1-0ubuntu3.5

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.