USN-1475-1: APT update

15 June 2012

apt update

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


APT now more thoroughly verifies imported keyrings.

Software Description

  • apt - Advanced front-end for dpkg


Georgi Guninski discovered that APT relied on GnuPG argument order and did not check GPG subkeys when validating imported keyrings via apt-key net-update. While it appears that a man-in-the-middle attacker cannot exploit this, as a hardening measure this update adjusts apt-key to validate all subkeys when checking for key collisions.

Update instructions

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

Ubuntu 12.04 LTS
apt - 0.8.16~exp12ubuntu10.1
Ubuntu 11.10
apt - 0.8.16~exp5ubuntu13.4
Ubuntu 11.04
apt -
Ubuntu 10.04 LTS
apt -
Ubuntu 8.04 LTS
apt - 0.7.9ubuntu17.5

To update your system, please follow these instructions:

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