h07 has discovered a vulnerability in Microsoft Windows, which can be exploited by malicious people to cause a DoS (Denial of Service).

The vulnerability is caused due to a NULL pointer dereference error in Windows NAT Helper Components (ipnathlp.dll). This can be exploited to crash the service via a specially crafted DNS query.

Successful exploitation requires that Internet Connection Sharing is enabled and the query is received from a client on the shared network interface.

The vulnerability is confirmed in a fully patched Windows XP SP2 system. Other versions may also be affected.

Solution
Use another way of sharing the Internet connection.

Provided and/or discovered by
h07

Changelog
Further details available to Secunia VIM customers

Original Advisory
http://milw0rm.com/exploits/2672

Deep Links
Links available to Secunia VIM customers