Ubuntu Security Notice 612-7 – USN-612-2 introduced protections for OpenSSH, related to the OpenSSL vulnerabilities addressed by USN-612-1. This update provides the corresponding updates for OpenSSH in Ubuntu 6.06 LTS. While the OpenSSL in Ubuntu 6.06 is not vulnerable, this update will block weak keys generated on systems that may have been affected themselves. 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.
You can download this advisory from the following link: https://packetstormsecurity.com/files/download/66524/USN-612-7.txt
Source: https://packetstormsecurity.com/files/66524/Ubuntu-Security-Notice-612-7.html