N/A - USN-612-10

A security issue affects the following Ubuntu releases:

Ubuntu 7.04 Ubuntu 7.10 Ubuntu 8.04 LTS

This advisory also applies to the corresponding versions of Kubuntu, Edubuntu, and Xubuntu.

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

Ubuntu 7.04:
openvpn 2.0.9-5ubuntu0.3

Ubuntu 7.10:
openvpn 2.0.9-8ubuntu0.3

Ubuntu 8.04 LTS:
openvpn 2.1~rc7-1ubuntu3.3

In general, a standard system upgrade is sufficient to effect the necessary changes.

Details follow:

USN-612-3 addressed a weakness in OpenSSL certificate and key generation in OpenVPN by adding checks for vulnerable certificates and keys to OpenVPN. A regression was introduced in OpenVPN when using TLS with password protected certificates which caused OpenVPN to not start when used with applications such as NetworkManager.

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.