USN-2155-1: OpenSSH vulnerability

25 March 2014

openssh vulnerability

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

  • Ubuntu 13.10
  • Ubuntu 12.10
  • Ubuntu 12.04 LTS
  • Ubuntu 10.04 LTS


OpenSSH incorrectly handled environment restrictions with wildcards.

Software Description

  • openssh - secure shell (SSH) for secure access to remote machines


Jann Horn discovered that OpenSSH incorrectly handled wildcards in AcceptEnv lines. A remote attacker could use this issue to possibly bypass certain intended environment variable restrictions.

Update instructions

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

Ubuntu 13.10
openssh-server - 1:6.2p2-6ubuntu0.2
Ubuntu 12.10
openssh-server - 1:6.0p1-3ubuntu1.1
Ubuntu 12.04 LTS
openssh-server - 1:5.9p1-5ubuntu1.2
Ubuntu 10.04 LTS
openssh-server - 1:5.3p1-3ubuntu7.1

To update your system, please follow these instructions:

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