USN-2164-1: OpenSSH vulnerability

7 April 2014

openssh vulnerability

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

  • Ubuntu 13.10
  • Ubuntu 12.10
  • Ubuntu 12.04 LTS

Summary

A malicious server could bypass OpenSSH SSHFP DNS record checking.

Software Description

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

Details

Matthew Vernon discovered that OpenSSH did not correctly check SSHFP DNS records if a server presented an unacceptable host certificate. A malicious server could use this issue to disable SSHFP checking.

Update instructions

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

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

To update your system, please follow these instructions: https://wiki.ubuntu.com/Security/Upgrades.

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

References