Ubuntu Security Notice USN-612-6
14th May, 2008
A security issue affects these releases of Ubuntu and its derivatives:
- Ubuntu 8.04 LTS
- Ubuntu 7.10
- Ubuntu 7.04
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
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.
The problem can be corrected by updating your system to the following package version:
- 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: https://wiki.ubuntu.com/Security/Upgrades.
After a standard system upgrade you need to restart openvpn to effect
the necessary changes.