Access Denied errors accessing IIS WMI provider from ASP - asp-classic

Question

I have a Windows 2003 server running IIS 6 and have some scripts that do automated setup and creation of websites. They are not working on a new server I cam commissioning (they already work happily on 3 other W2K3 servers). The problem appear to boil down to WMI security on the IIS provider. The ASP code below represents the problem (although it is not the original code that causes the problem - this is a simplified demonstration of the problem).
Set wmiProvider = GetObject("winmgmts:\\.\root\MicrosoftIISv2")
If wmiProvider is Nothing Then
Response.Write "Failed to get WMI provider MicrosoftIISv2<br>"
End If
Response.Write "Querying for IISWebService...<br>"
Set colItems = wmiProvider.ExecQuery("Select * From IISWebServer",,0)
Response.Write "Error: " & Hex(Err.Number) & " (" & Err.Description & ")<br>"
If I run this in my browser, I get an access denied error reported after the ExecQuery call. I have set WMI access for the IUSR_ user from the Root branch all the way down. In fact, I can query for IP address information using the CIMV2 provider quite happily. If I put the IUSR user in the machine admins group it all works, but I don't really want to do that.
This must be a DCOM/WMI security problem, but I can't work out what else there is. Can anyone shed any light?

Answer 1

After reading G. Stoynev's comment asking if any events were logged in the Windows Logs, I checked the event logs on the server to which I'm attempting to access IIS remotely via WMI, and lo and behold I found an event with the following text:
Access to the root\WebAdministration namespace was denied because the namespace is marked with RequiresEncryption but the script or application attempted to connect to this namespace with an authentication level below Pkt_Privacy. Change the authentication level to Pkt_Privacy and run the script or application again.
See the code in this answer to the related SO question c# - "Access is denied" Exception with WMI.
Here's some example C# code that I added that seemed to resolve this issue for me:
ConnectionOptions options = new ConnectionOptions();
options.Authentication = AuthenticationLevel.PacketPrivacy;
ManagementScope managementScope = new ManagementScope(#"\\remote-server\root\WebAdministration", options);
// ...

Answer 2

If this is something that you intend to run as a tool for yourself or your admin (as opposed to the unwashed anonymous masses), here is a way I have used in the past (YMMV):
Set up a new directory in your website (e.g. /SiteCreate) and place your WMI scripts there
Configure a Windows user that has appropriate rights (probably admin in this case but you should use whatever is pertinent to your app)
Turn off the anonymous access to the directory you created in step 1 and then set the security to allow access only to the user you created in step 2 (turn on the authentication for that directory)
Now, when you navigate to that directory in your browser, you should get a login prompt. When you enter the username/password you created in step 2 your script will have the appropriate rights to perform your WMI requests.

Answer 3

Not a DCOM issue, more so a WMI security and encryption issue. Try changing the GetObject moniker to include impersonation and pktPrivacy, eg:
Set wmiProvider = GetObject("winmgmts:{impersonationLevel=impersonate;authenticationLevel=pktPrivacy}!\root\MicrosoftIISv2")
Refer to the follow MS article for more info:
http://msdn.microsoft.com/en-us/library/aa393618(v=vs.85).aspx