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We strongly recommend that all users upgrade to Microsoft Internet Information Services (IIS) version 7.0 running on Microsoft Windows Server 2008. IIS 7.0 significantly increases Web infrastructure security. For more information about IIS security-related topics, visit the following Microsoft Web site:
IMPORTANT: If you download and install the fix included in this article onto a computer running IIS 3.0, the IIS 3.0 Web, FTP, and Proxy services will fail. This fix should only be applied to computers running IIS 4.0 or later. To verify your version of IIS, follow these steps:
Click Start, click Settings, and then click Control Panel.
Double-click Administrative Tools, and then click the Services icon.
In the Services list, locate the IIS Admin Service.
If the IIS Admin Service is listed, download and apply the fix included in this article.
If the IIS Admin Service is not listed, your version of IIS is not vulnerable to the problem that is corrected by these fixes. Therefore, no action is needed. IIS 3.0 is not vulnerable and does not need this fix. If the IIS Admin Service is not listed, your version of IIS is not vulnerable to this particular problem that is corrected by these fixes. However, IIS 3 is no longer a supported product and has no security fixes for other problems.
A security vulnerability exists in Internet Information Services 5.0 and Internet Information Server 4.0 that may allow a malicious user to gain access to files and folders that are located on the logical drive containing the Web folders. This vulnerability can potentially allow a Web site visitor to take a wide range of destructive actions against it, including running programs on it.
Customers who have applied the patch from MS00-057 are already protected against this vulnerability and do not need to take additional action. If you are using IIS 4.0 or IIS 5.0, Microsoft strongly urges you to apply the patch immediately, if you have not already done so. For more information about how to obtain this patch, click the following article number to view the article in the Microsoft Knowledge Base:
269862 Patch released for canonicalization error issue
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
Additional information about this issue is available from thefollowing Microsoft Web site: