Ubuntu Security Notice 1475-1 - 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.
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Ubuntu Security Notice USN-1475-1
June 15, 2012
apt update
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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:
APT now more thoroughly verifies imported keyrings.
Software Description:
- apt: Advanced front-end for dpkg
Details:
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 0.8.13.2ubuntu4.5
Ubuntu 10.04 LTS:
apt 0.7.25.3ubuntu9.12
Ubuntu 8.04 LTS:
apt 0.7.9ubuntu17.5
In general, a standard system update will make all the necessary changes.
References:
http://www.ubuntu.com/usn/usn-1475-1
https://launchpad.net/bugs/1013128
Package Information:
https://launchpad.net/ubuntu/+source/apt/0.8.16~exp12ubuntu10.1
https://launchpad.net/ubuntu/+source/apt/0.8.16~exp5ubuntu13.4
https://launchpad.net/ubuntu/+source/apt/0.8.13.2ubuntu4.5
https://launchpad.net/ubuntu/+source/apt/0.7.25.3ubuntu9.12
https://launchpad.net/ubuntu/+source/apt/0.7.9ubuntu17.5