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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:
A security patch has been released that resolves a canonicalization error that can allow a malicious user to gain additional permissions to certain types of files that are hosted on a Web server.
For this vulnerability to be exploited, several factors are involved:
Only file types that are implemented through ISAPI extensions are affected. It does not affect static Web page or non-Web file types such as .exe, .doc, or .bat.
It only affects servers that expose a Web folder structure that mirrors the physical folder structure on the server. It does not impact virtual directories.
It does not allow arbitrary permissions to be selected, only permissions present on an ancestor folder.
It provides no ability to enumerate the server and locate files that can be affected by the vulnerability.
In addition to the above, this security patch also corrects the vulnerability described by the following article in the Microsoft Knowledge Base:
276489 Patch available for Web server folder traversal vulnerability
Microsoft Exchange 2000 Server users and Microsoft SharePoint Portal Server 2001 users
Both Exchange 2000 and SharePoint Portal Server 2001 have problems with an older verison of this hotfix. A new update for the security patch for these products is available at the following Microsoft Web page:
For additional information about how to download Microsoft Support files, click the following article number to view the article in the Microsoft Knowledge Base:
119591 How to Obtain Microsoft Support Files from Online Services
Microsoft scanned this file for viruses. Microsoft used the most current virus-detection software that was available on the date that the file was posted. The file is stored on security-enhanced servers that help to prevent any unauthorized changes to the file. The English version of this fix should have the following file attributes or later:
Date Time Version Size File name ----------------------------------------------------- 08-09-2000 1:02pm 5.0.2195.2103 357,136 W3svc.dll
Microsoft Windows NT Server version 4.0, Terminal Server Edition
To resolve this problem, obtain the Windows NT Server 4.0, Terminal Server Edition, Security Rollup Package (SRP). For more information about the SRP, click the following article number to view the article in the Microsoft Knowledge Base:
317636 Windows NT Server 4.0, Terminal Server Edition, Security Rollup Package
Microsoft has confirmed that this is a problem in Internet Information Services 5.0 and Internet Information Server 4.0.
Additional information about this issue is available from the following Microsoft Web site: