USN-2865-1: GnuTLS vulnerability

8 January 2016

gnutls26, gnutls28 vulnerability

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

  • Ubuntu 15.04
  • Ubuntu 14.04 LTS
  • Ubuntu 12.04 LTS

Summary

GnuTLS could be made to expose sensitive information over the network.

Software Description

  • gnutls28 - GNU TLS library
  • gnutls26 - GNU TLS library

Details

Karthikeyan Bhargavan and Gaetan Leurent discovered that GnuTLS incorrectly allowed MD5 to be used for TLS 1.2 connections. If a remote attacker were able to perform a man-in-the-middle attack, this flaw could be exploited to view sensitive information.

Update instructions

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

Ubuntu 15.04
libgnutls-deb0-28 - 3.3.8-3ubuntu3.2
libgnutls-openssl27 - 3.3.8-3ubuntu3.2
libgnutlsxx28 - 3.3.8-3ubuntu3.2
Ubuntu 14.04 LTS
libgnutls-openssl27 - 2.12.23-12ubuntu2.4
libgnutls26 - 2.12.23-12ubuntu2.4
libgnutlsxx27 - 2.12.23-12ubuntu2.4
Ubuntu 12.04 LTS
libgnutls-openssl27 - 2.12.14-5ubuntu3.11
libgnutls26 - 2.12.14-5ubuntu3.11
libgnutlsxx27 - 2.12.14-5ubuntu3.11

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