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.
This vulnerability only affects operating systems which (like Ubuntu) are based on Debian. However, other systems can be indirectly affected if weak keys are imported into them.
13 May 2008
A security issue affects these releases of Ubuntu and its derivatives:
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.
This vulnerability only affects operating systems which (like Ubuntu) are based on Debian. However, other systems can be indirectly affected if weak keys are imported into them.
We consider this an extremely serious vulnerability, and urge all users to act immediately to secure their systems. (CVE-2008-0166)
== Who is affected ==
Systems which are running any of the following releases:
and have openssh-server installed or have been used to create an OpenSSH key or X.509 (SSL) certificate.
All OpenSSH and X.509 keys generated on such systems must be considered untrustworthy, regardless of the system on which they are used, even after the update has been applied.
This includes the automatically generated host keys used by OpenSSH, which are the basis for its server spoofing and man-in-the-middle protection.
The problem can be corrected by updating your system to the following package versions:
To update your system, please follow these instructions: https://wiki.ubuntu.com/Security/Upgrades.
In general, a standard system upgrade is sufficient to effect the necessary changes.
Vulmon