WMI Access Denied on XP

Question

Our application uses bunch of WMI calls. When using guest account connecting to local WMI server fails with ACCESS_DENIED, this works fine with user account and above. How to access WMI server under guest account?

I added guest account to allow full access using WMIMGMT.MSC but still I am getting access denied errors.

Any suggetions?

Answer 1

Are you sure you want to give the guest account WMI remote access? I'm not sure the security implications of that...

Anyways, I think you'll need to give remote DCOM access for the guest account on the target machine. (It's been a long time for me on this one so I'm not sure this will solve everything, and I don't remember all the details so I'm leaning on this forum post)

1. Open Component Services (for local machine, can run dcomcnfg.exe)
2. Navigate to DCOM Config (Component Services > Computers > My Computer > DCOM Config)
3. In the details pane find "Windows Management and Instrumentation" (switching to list view helps). Right click and select 'Properties'
4. Go to the 'Security' tab and note the 'Launch And Activation Permissions', and 'Access Permissions' -- do the following thing for both of them:
   • Select 'Customize' if not already selected
   • Click Edit
   • In the Security properties page, click Add
   • In the Select Users or Groups popup, add the guest account (for local machine it's just type 'guest' and click 'Check Names' then 'OK', not sure about server in a domain)
   • Back in the Security properties page, note that Guest has less permissions by default than 'Everyone'. Give the permissions that you want: sounds like maybe 'Remote Launch' and 'Remote Activation'. I'd probably do some testing with whether 'Local Activation' is needed too.

Once again even if it works for you I'd look carefully at whether there are security issues with giving this kind of remote permission to the Guest account.

Hope this helps,
Daryn.