FIX: Error message when you try to visit an ASP.NET 2.0-based Web page: "HttpException (0x80004005): '/HandlerTest/WebForm1.aspx/a:b' is not a valid virtual path"

When you try to visit a Microsoft ASP.NET 2.0-based Web page, you may receive an error message that resembles the following:This problem occurs if the virtual path in the URL contains one of the following symbols:

• Colon (:)
• Asterisk (*)

For example, this problem occurs when you try to visit one of the following URLs:

• http://www.adventure:works.com/test.aspx
• http://www.adventure*works.com/test.aspx

Note This problem occurs even if you use the method that is described in Microsoft Knowledge Base article 826437 to set the value of the following registry subkey to 1:

This problem occurs because of a change in ASP.NET 2.0. This change causes ASP.NET 2.0 to explicitly check any symbols in the virtual path in the URL when ASP.NET 2.0 validates the URL.

Hotfix information

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

To resolve this problem immediately, contact Microsoft Customer Support Services to obtain the hotfix. For a complete list of Microsoft Customer Support Services telephone numbers and information about support costs, visit the following Microsoft Web site:Note In special cases, charges that are ordinarily incurred for support calls may be canceled if a Microsoft Support Professional determines that a specific update will resolve your problem. The usual support costs will apply to additional support questions and issues that do not qualify for the specific update in question.

Prerequisites

You must have Microsoft .NET Framework 2.0 installed to apply this hotfix.

Restart requirement

You do not have to restart the 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 item in Control Panel.

The .NET Framework 2.0, x86-based versions

The .NET Framework 2.0, x64-based versions

The .NET Framework 2.0, Itanium-based versions

Registry information

Warning Serious problems might occur if you modify the registry incorrectly by using Registry Editor or by using another method. These problems might require that you reinstall the operating system. Microsoft cannot guarantee that these problems can be solved. Modify the registry at your own risk.

After you apply this hotfix, you must enable it by setting the value of the VerificationCompatibility entry of the following registry subkey to 1:Important If you enable this hotfix, ASP.NET will not automatically check whether a URL contains special symbols. Therefore, you increase the attack surface of the application. You should not enable this hotfix unless the application requires that you take this action. If you enable this hotfix, you must manually make sure that URLs are handled correctly.

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

For more information about software update terminology, click the following article number to view the article in the Microsoft Knowledge Base: