USN-3065-1: Libgcrypt vulnerability

18 August 2016

libgcrypt11, libgcrypt20 vulnerability

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

  • Ubuntu 16.04 LTS
  • Ubuntu 14.04 LTS
  • Ubuntu 12.04 LTS


Libgcrypt incorrectly generated random numbers.

Software Description

  • libgcrypt20 - LGPL Crypto library
  • libgcrypt11 - LGPL Crypto library


Felix Dörre and Vladimir Klebanov discovered that Libgcrypt incorrectly handled mixing functions in the random number generator. An attacker able to obtain 4640 bits from the RNG can trivially predict the next 160 bits of output.

Update instructions

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

Ubuntu 16.04 LTS
libgcrypt20 - 1.6.5-2ubuntu0.2
Ubuntu 14.04 LTS
libgcrypt11 - 1.5.3-2ubuntu4.4
Ubuntu 12.04 LTS
libgcrypt11 - 1.5.0-3ubuntu0.6

To update your system, please follow these instructions:

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