Request Restrictions can't be set for a wildcard ISAPI in IIS 7.0 and later versions
This article helps you resolve the problem where the Request Restrictions feature of handler mappings is not available for a Wildcard Internet Server Application Programming Interface (ISAPI) extension on Microsoft Internet Information Services (IIS) 7.0 and later versions.
Original product version: Internet Information Services 7.0 and later versions
Original KB number: 2725025
The Request Restrictions functionality of handler mappings cannot be set for a Wildcard ISAPI extension on IIS 7.0 and later versions. The Request Restrictions feature and the Invoke handler only if the request maps to option on IIS 7.0 and later versions provide the same functionality of the Verify that file exists checkbox on IIS 6.
If the Request Restrictions are set by editing the IIS 7.0 or a later version configuration and adding the sections
resourceType for the wildcard ISAPI extension handler, you may experience unexpected behavior browsing pages that are not handled by the Wildcard ISAPI extension, such as
StaticFile handler requests.
The option to add Request Restrictions for a Wildcard ISAPI are not available through the IIS Manager.
This behavior is by design on IIS 7.0 and later versions. You cannot add Request Restrictions for a Wildcard ISAPI extension on IIS 7.0 and later versions either through the IIS manager or by changing configuration. Adding Request Restrictions for a Wildcard ISAPI extension by editing the configuration is not supported on IIS 7.0 and later versions.
If your Wildcard ISAPI extension uses the Verify that file exists functionality of IIS 6, you will need to manually perform the Verify that file exists functionality inside your wildcard ISAPI extension. This is because the feature to add request restrictions for a Wildcard ISAPI is not available on IIS 7.0 and later versions.
For example, if you intend to run your ISAPI extension on IIS 7.0 or a later version and if the purpose of using the Verify that file exists was to deny users who did not have permissions to view a particular file on IIS 6, you will need to perform those same checks manually in your wildcard ISAPI extension and deny users.