USN-612-6: OpenVPN regression

14 May 2008

openvpn regression

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

  • Ubuntu 8.04 LTS
  • Ubuntu 7.10
  • Ubuntu 7.04

Software Description

  • openssl-blacklist
  • openvpn


USN-612-3 addressed a weakness in OpenSSL certificate and keys generation in OpenVPN by adding checks for vulnerable certificates and keys to OpenVPN. A regression was introduced in OpenVPN when using TLS, multi-client/server mode, and specifying a user or group which caused OpenVPN to not start when using valid SSL certificates.

It was also found that openssl-vulnkey from openssl-blacklist would fail when stderr was not available. This caused OpenVPN to fail to start when used with applications such as NetworkManager.

This update fixes these problems. We apologize for the inconvenience.

Original advisory details:

A weakness has been discovered in the random number generator used by OpenSSL on Debian and Ubuntu systems. As a result of this weakness, certain encryption keys are much more common than they should be, such that an attacker could guess the key through a brute-force attack given minimal knowledge of the system. This particularly affects the use of encryption keys in OpenSSH, OpenVPN and SSL certificates.

Update instructions

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

Ubuntu 8.04 LTS
openssl-blacklist - 0.1-0ubuntu0.8.04.2
openvpn - 2.1~rc7-1ubuntu3.2
Ubuntu 7.10
openssl-blacklist - 0.1-0ubuntu0.7.10.2
openvpn - 2.0.9-8ubuntu0.2
Ubuntu 7.04
openssl-blacklist - 0.1-0ubuntu0.7.04.2
openvpn - 2.0.9-5ubuntu0.2

To update your system, please follow these instructions:

After a standard system upgrade you need to restart openvpn to effect the necessary changes.