Critical flaw discovered in IIS webdav. patch it!

Yes this is the kind of flaw that hackers write code for and caused CodeRed and SQL Slammer. So patch your systems now!

Microsoft Windows 2000 supports the World Wide Web Distributed Authoring and Versioning (WebDAV) protocol. WebDAV, defined in RFC 2518, is a set of extensions to the Hyper Text Transfer Protocol (HTTP) that provide a standard for editing and file management between computers on the Internet. A security vulnerability is present in a Windows component used by WebDAV, and results because the component contains an unchecked buffer.

An attacker could exploit the vulnerability by sending a specially formed HTTP request to a machine running Internet Information Server (IIS). The request could cause the server to fail or to execute code of the attacker???????ˉs choice. The code would run in the security context of the IIS service (which, by default, runs in the LocalSystem context).

Although Microsoft has supplied a patch for this vulnerability and recommends customers install the patch immediately, additional tools and preventive measures have been provided that customers can use to block the exploitation of this vulnerability while they are assessing the impact and compatibility of the patch. These temporary workarounds and tools are discussed in the ???????°Workarounds???????± section in the FAQ below.

Mitigating factors:

URLScan, which is a part of the IIS Lockdown Tool will block this attack in its default configurations

The vulnerability can only be exploited remotely if an attacker can establish a web session with an affected server

Download : Windows 2000 Security Patch: IIS Remote Exploit from ntdll.dll Vulnerability

View : Microsoft Security Bulletin MS03-007