USN-1570-1: GnuPG vulnerability

Ubuntu Security Notice USN-1570-1

17th September, 2012

gnupg, gnupg2 vulnerability

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

  • Ubuntu 12.04 LTS
  • Ubuntu 11.10
  • Ubuntu 11.04
  • Ubuntu 10.04 LTS
  • Ubuntu 8.04 LTS

Summary

GnuPG could be tricked into downloading a different key when downloading from a key server.

Software description

  • gnupg - GNU privacy guard - a free PGP replacement
  • gnupg2 - GNU privacy guard - a free PGP replacement

Details

It was discovered that GnuPG used a short ID when downloading keys from a
keyserver, even if a long ID was requested. An attacker could possibly use
this to return a different key with a duplicate short key id.

Update instructions

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

Ubuntu 12.04 LTS:
gnupg2 2.0.17-2ubuntu2.12.04.1
gnupg 1.4.11-3ubuntu2.1
Ubuntu 11.10:
gnupg2 2.0.17-2ubuntu2.11.10.1
gnupg 1.4.11-3ubuntu1.11.10.1
Ubuntu 11.04:
gnupg2 2.0.14-2ubuntu1.2
gnupg 1.4.11-3ubuntu1.11.04.1
Ubuntu 10.04 LTS:
gnupg2 2.0.14-1ubuntu1.4
gnupg 1.4.10-2ubuntu1.1
Ubuntu 8.04 LTS:
gnupg2 2.0.7-1ubuntu0.2
gnupg 1.4.6-2ubuntu5.1

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

LP: 1016643