USN-1923-1: GnuPG, Libgcrypt vulnerability

1 August 2013

gnupg, libgcrypt11 vulnerability

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

  • Ubuntu 13.04
  • Ubuntu 12.10
  • Ubuntu 12.04 LTS
  • Ubuntu 10.04 LTS


GnuPG and Libgcrypt could be made to expose sensitive information.

Software Description

  • gnupg - GNU privacy guard - a free PGP replacement
  • libgcrypt11 - LGPL Crypto library - runtime library


Yuval Yarom and Katrina Falkner discovered a timing-based information leak, known as Flush+Reload, that could be used to trace execution in programs. GnuPG and Libgcrypt followed different execution paths based on key-related data, which could be used to expose the contents of private keys.

Update instructions

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

Ubuntu 13.04
gnupg - 1.4.12-7ubuntu1.1
libgcrypt11 - 1.5.0-3ubuntu2.2
Ubuntu 12.10
gnupg - 1.4.11-3ubuntu4.2
libgcrypt11 - 1.5.0-3ubuntu1.1
Ubuntu 12.04 LTS
gnupg - 1.4.11-3ubuntu2.3
libgcrypt11 - 1.5.0-3ubuntu0.2
Ubuntu 10.04 LTS
gnupg - 1.4.10-2ubuntu1.3
libgcrypt11 - 1.4.4-5ubuntu2.2

To update your system, please follow these instructions:

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