Vulnerability Note VU#794580

Microsoft DNS Client buffer overflow

Original Release date: 08 Aug 2006 | Last revised: 08 Aug 2006


The Microsoft DNS Client service contains a remote code execution vulnerability that could allow a remote attacker to take complete control of the affected system.


From Microsoft TechNet:

    The Domain Name System (DNS) client service resolves and caches DNS names. The DNS client service must be running on every computer that will perform DNS name resolution. The ability to resolve DNS names is crucial for locating domain controllers in Active Directory domains. The DNS client service is also critical for locating devices identified using DNS name resolution.

The DNS client layer contains an unchecked buffer which could be exploited by a remote and unauthenticated attacker to gain access to the system.


A remote, unauthenticated attacker can gain complete control of a system, including the ability to install programs, view, change or delete data, or create new accounts, by one of the following means:

  1. Sending a specially crafted DNS communication to an affected system from a subnet between the target host and DNS server; or
  2. Convince the target host to make a DNS request to receive a specially crafted record response from an attacking server.



Apply the update provided by Microsoft. Refer to Microsoft Security Bulletin MS06-041 for more information.

Block the following DNS related records at network gateways:

  • ATMA
  • TXT
  • X25

Systems Affected (Learn More)

VendorStatusDate NotifiedDate Updated
Microsoft CorporationAffected08 Aug 200608 Aug 2006
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



This vulnerability was reported by Microsoft, who in turn credit Mark Dowd of ISS X-Force for reporting this vulnerability.

This document was written by Joseph W Pruszynski.

Other Information

  • CVE IDs: CVE-2006-3441
  • Date Public: 08 Aug 2006
  • Date First Published: 08 Aug 2006
  • Date Last Updated: 08 Aug 2006
  • Severity Metric: 6.75
  • Document Revision: 20


If you have feedback, comments, or additional information about this vulnerability, please send us email.