BIND Update: Important Advisory on DNS Cache Poisoning Risks

The InfoCon is currently set at yellow in response to the DNS cache poisoning issues that we have been reporting on for the last several days. We originally went to yellow because we were uncertain of the mechanisms that allowed seemingly "secure" systems to be vulnerable to this issue. Now that we have a better handle on the mechanisms, WE WANT TO GET THE ATTENTION OF ISPs AND ANY OTHERS WHO RUN DNS SERVERS THAT MAY ACT AS FORWARDS FOR DOWNSTREAM Microsoft DNS SYSTEMS. If you are running BIND, please consider updating to Version 9.

We have received more technical details on the software configurations that are vulnerable. Thanks to Microsoft for clarifying details on Windows DNS and thanks to numerous others for reporting. We try to get all the technical details right before publishing information on attacks like this, but if we waited until we were 100% sure all the time, we would never be able to notify the community when the attacks are actually happening.

On Windows 2000 SP3 and above, the DNS server DOES protect against DNS cache pollution by default. The registry key to protect against the poisoning is not necessary: the value is TRUE if the registry key does not exist. Microsoft has now corrected the KB article that we published earlier with this information.

The link for this article located at SANS is no longer available.