FIX: The isolated configuration file for an application pool contains configuration data for Web sites of other application pools in IIS 7.0

Consider the following scenario:

• You host a Web site in Microsoft Internet Information Service (IIS) 7.0 on a computer that is running Windows Vista or Windows Server 2008. The Web site is running in an application pool.
• The Web site receives an access request for the first time.
• An isolated configuration file is created for the application pool. The file contains configuration data for the Web site.
  
  Notes
  • By default, isolated configuration files are located in the following directory:
    %SystemDrive%\Inetpub\Temp\Apppools
  • The configuration data for the Web site is wrapped in the Location element.

In this scenario, the configuration file unexpectedly contains configuration data for Web sites in other application pools.

The isolated configuration file of the application pool is accessed only by Web sites in the same application pool. Web sites in other application pools cannot access the file. This causes an incorrect exposure of information.

For example, a Web site that is running in the DefaultAppPools application pool receives an access request. However, the DefaultAppPools.config file contains configuration data for the Web sites that are running in the DefaultAppPools application pool and also configuration data for the Web sites that are running in the Classic .NET AppPool application pool. Therefore, the configuration data for the Web sites in the Classic .NET AppPool application pool is exposed.

When a Web site in an application pool receives the first request, the Windows Process Activation Service (WAS) creates an isolated configuration file. The file is created by filtering the configuration data for the application pool in the applicationHost.config file. The problem that is described in the Symptoms section occurs because the Location elements in the applicationHost.config file are not parsed correctly when the WAS creates the isolated configuration file.

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 the problem described in this article. 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

You must have Internet Information Service (IIS) 7.0 installed to apply this hotfix.

To apply this hotfix on a computer that is running Windows Vista, you also must have Windows Vista Service Pack 1 (SP1) or Windows Vista Service Pack 2 (SP2) installed. For more information, click the following article number to view the article in the Microsoft Knowledge Base: - No additional prerequisites are required for computers that are running Windows Server 2008.

Restart requirement

You must restart the computer if the IIS is running when you apply this hotfix.

Hotfix replacement information

This hotfix does not replace 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 item in Control Panel.

For all supported x86-based versions for Windows Vista and Windows Server 2008

For all supported x64-based versions of Windows Vista and Windows Server 2008

For all supported Itanium-based versions of Windows Server 2008

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

You can specify a custom location for the isolated configuration file in IIS 7.0. For more information, click the following article number to view the article in the Microsoft Knowledge Base: