Vulnerability Note VU#319331

Microsoft Windows DNS Server response validation vulnerability

Original Release date: 10 Mar 2009 | Last revised: 17 Mar 2009


The Microsoft Windows DNS server contains a response validation vulnerability. If successfully exploited, this vulnerability may allow an attacker to poison the affected DNS server's cache.


The Domain Name System (DNS) is responsible for translating host names to IP addresses (and vice versa) and is critical for the normal operation of internet-connected systems.

Per Microsoft Security Bulletin MS09-008:

    A response validation vulnerability exists in Windows DNS Server. The vulnerability could allow an unauthenticated remote attacker to send specially crafted queries to a DNS server so as to allow greater predictability of transaction IDs used by the DNS server and thus to redirect Internet traffic from legitimate locations.


An attacker may be able to insert arbitrary values in the DNS cache. An attacker with the ability to conduct a successful attack can cause a nameserver's clients to contact the incorrect, and possibly malicious, hosts for particular services. Consequently, web traffic, email, and other important network data can be redirected to systems under the attacker's control.


Microsoft has released an update to address this issue. See for more information.

Systems Affected (Learn More)

VendorStatusDate NotifiedDate Updated
Microsoft CorporationAffected-10 Mar 2009
If you are a vendor and your product is affected, let us know.

CVSS Metrics (Learn More)

Group Score Vector
Base N/A N/A
Temporal N/A N/A
Environmental N/A N/A



Information from Microsoft Security Bulletin MS09-008 was used in this report. Microsoft credits Kevin Day and Dave Dagon for providing assistance with this issue.

This document was written by Ryan Giobbi.

Other Information

  • CVE IDs: CVE-2009-0234
  • Date Public: 10 Mar 2009
  • Date First Published: 10 Mar 2009
  • Date Last Updated: 17 Mar 2009
  • Severity Metric: 10.13
  • Document Revision: 21


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