Web requests may not obtain the correct security context on a server that is running Windows Server 2003

If you have two Web sites that use Windows authentication, and these Web sites are running on different ports, Web requests from one Web site to the other Web site may not obtain the correct security context. Some server variables such as REMOTE_USER may have the value of NULL. This condition causes any code that requests the REMOTE_USER server variable to return a null value instead of the authenticated user.

This problem occurs because of a code defect in the QueryContextAttributes function. When a call that uses the SECPKG_ATTR_NAMES attribute is made to the QueryContextAttributes function to request a user name, the QueryContextAttributes function may return an empty user name instead.

Hotfix information

A supported hotfix is available from Microsoft. However, this hotfix is intended to correct only the problem that is described in this article. Apply this hotfix only to systems that are experiencing this specific problem. This hotfix might receive additional testing. Therefore, if you are not severely affected by this problem, we recommend that you wait for the next software update that contains this hotfix.

If the hotfix is available for download, there is a "Hotfix download available" section at the top of this Knowledge Base article. If this section does not appear, contact Microsoft Customer Service and Support to obtain the hotfix.

Note If additional issues occur or if any troubleshooting is required, you might have to create a separate service request. The usual support costs will apply to additional support questions and issues that do not qualify for this specific hotfix. For a complete list of Microsoft Customer Service and Support telephone numbers or to create a separate service request, visit the following Microsoft Web site: Note The "Hotfix download available" form displays the languages for which the hotfix is available. If you do not see your language, it is because a hotfix is not available for that language.

Prerequisites

No prerequisites are required.

Restart requirement

You must restart your computer after you apply this hotfix.

Hotfix replacement information

This hotfix does not replace any other hotfixes.

File information

The English version of this hotfix has the file attributes (or later file attributes) that are listed in the following table. The dates and times for these files are listed in coordinated universal time (UTC). When you view the file information, it is converted to local time. To find the difference between UTC and local time, use the Time Zone tab in the Date and Time tool in Control Panel.

Microsoft Windows Server 2003, 32-bit editions

Microsoft Windows Server 2003, 64-Bit Enterprise Edition

Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.

For additional information, click the following article number to view the article in the Microsoft Knowledge Base: