USN-2821-1: GnuTLS vulnerability

Ubuntu Security Notice USN-2821-1

30th November, 2015

gnutls26 vulnerability

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

  • Ubuntu 14.04 LTS
  • Ubuntu 12.04 LTS


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

Software description

  • gnutls26 - GNU TLS library


It was discovered that GnuTLS incorrectly validated the first byte of
padding in CBC modes. A remote attacker could possibly use this issue to
perform a padding oracle attack.

Update instructions

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

Ubuntu 14.04 LTS:
libgnutls26 2.12.23-12ubuntu2.3
Ubuntu 12.04 LTS:
libgnutls26 2.12.14-5ubuntu3.10

To update your system, please follow these instructions:

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


LP: 1510163