Note - this is tested on a Windows 2003 R2 domain.
Further note - I have corrected it a bit - specifically the problem applies ONLY to Domain Admins - see http://www.myfriedmind.com/techBlog/2009/10/20/UACAndDomainAdminsPermissionsIssueOrPocketFullOfKryptonite.aspx for more info.
A while ago I noticed something odd on my Windows 2008 clustered file server. When I tried to open the clustered drive that I was using to hold my shares from the box while logged in as a non-default admin (hereafter referred to as NDA) I got a message stating “Access is denied”.
This only happened if I was logged into the box itself in the server room or via Remote Desktop. I could access the hidden share for that drive remotely with no problem. Also, if I logged on with the built-it administrator account (hereafter referred to as BIAA) I had no problem. Finally, if I disabled the User Access Control (UAC) I could access the drive with the NDA.
Originally I thought that this might be caused by it being clustered, but Symon Perriman from MSoft assured me that he had not heard of this. Then I thought it might be because storage we were using and the driver – EMC PowerPath. But I put off any further testing until I had time to work on a non-production box and to wait for W08R2 to see if that would make a difference.
First the good news – it does not have to do with clustering. Now the bad news – it might be a serious issue.
The basic issue is that the UAC, on both W08 and W08R2 appears to have issues enumerating membership for certain groups. What is especially unfortunate is that Domain Admins is one of those groups that it has trouble enumerating.
My Discovery of the Issue
When I created the new box to test I was initially unable to replicate the problem. It was not until I looked closer at the clustered drive on the original box that I realized that the problem had to do with permissions. Since the clustered drive would contain folders that would limit who would have access I had removed the “Users” group, leaving “CREATOR OWNER”, “SYSTEM”, “Administrators” (for that box) untouched. I then added “Domain Admins” with Full Control since this would be clustered and I did not want to rely on the “Administrators” of one of the nodes for perms. My plan was to create the shares, inherit from above, and add the appropriate security groups.
Unfortunately, with the UAC turned on I could no longer access the drive even though the account that I was using was a member of Domain Admins, albeit not the BIAA. I got a very strongly worded “NO”.
I replicated the permissions on my test box and discovered the same issue. I then added Everyone to the root of the drive with “Read” permissions and suddenly the NDA could access the drive.
By POE (process of elimination <g>) I determined that of the four permissions included in “Read” – “Traverse Folder / execute file”, “List folder / read data”, “Read attributes”, and “Read extended attributes” – I only needed the middle two – “List folder / read data” and “Read attributes”.
Hmm, I wondered if the issue could be that some special account was being used by the UAC to check for the drive. So I removed the “Everyone” group and added the NDA with those two specific perms. I could access the drive. So it appeared not to be an issue with a unique account, but more likely that the Domain Admins membership could not be enumerated. Maybe.
So I added an old Global Security group that the NDA belonged to (after removing the NDA) with the necessary perms. That worked. So I removed that, added an old Local Security group that the old Global security group belonged to. That worked.
I am stretching for possible causes. I can conceive of no reason why the Domain Admins membership could not be enumerated when other older groups have no issue, even when the NDA is a member of a member of a group. The only thing that strikes me is that all the old accounts I have used do not have spaces. Stretching, I know, but there has to be SOME reason.
I create two new Global Security groups – “PermTest” and “Perm Test”, one with a space one without. I add the NDA to each and try each of the, granting them the necessary perms. Neither one worked. So that blows that theory. Just to put a nail in the coffin I add “Domain Users” and that works. Further testing with Msoft and I catch that I have to Log OFF and BACK ON for this. Ooops. Those new accounts work, but Domain Admins still will not.
So far (when the UAC is turned on and accessing with the NDA):
Works
- Directly adding NDA
- Adding Everyone
- Adding Domain Users
- Adding Old Global Security groups containing NDA
- Adding Old Local Security groups containing old Global Security groups containing NDA
- Adding anny counter OTHER than Domain Admins
Does not work
I open up ADSIEdit to look at the properties of “Domain Admins” vs “Domain Users”, I specifically want to see when it says the whenCreated and the whenChanged attributes are. It turns out that although they both share the same whenCreated date, the “Domain Admins” whenChanged is more recent. Except that the old Global Security group containing the NDA has been changed more recently and that one works.
So that is a dead end.
And why does the default administrator account have no problem even with UAC turned on?
Verification by another forest
I want a totally isolated confirmation so I contact a buddy of mine down in Ohio (thanks Stuart) who is also running a w03 network with a w08 member server on it. He runs into the exact same problem. So the issue does not appear to be bad media or erroneous implementation, unless we both made the exact same mistakes.
Moving to subfolders
I move my study to subfolders. I create a subfolder on a local drive, remove Users, add Domain Admins and test that. I get this message “You don’t currently have permission to access this folder”. If I choose “Continue” it adds the NDA account with Full Control and lets me in.
A closer look at the UAC
It is past time now that we delve into the UAC which seems to be giving us such problems.
In the original w08 it was located in the Control Panel under “User Accounts” and you had two options there – on or off. In w08r2 it is still located in the Control Panel but it has now been moved to “System and Security” and now you have four options (see image).

Quick testing on w08r2 soon reveals that the only time that the NDA can access the drive via “Domain Admins” perms is when the UAC is all the way at the bottom (ie turned completely off).
What you may not know is that behind the scenes these apparently limited choices actually control ten different settings in the Local Security Policy. You can access your Local Security Policy by going to your “Administrative Tools”. Look under Local Policies, Security Options and at the bottom you will find the entries I am talking about.

First, let me draw your attention to the very top one – “Admin Approval Mode for the Built-in Administrative account”. This is the source of that odd exception – that the built-in administrative account can access the drive regardless of the UAC settings. This is set to Disabled and is ALWAYS set to Disabled regardless of the changes you make in the Control Panel. The only way to change it to Enabled is to change it here.
What will happen if it gets changed from Disabled to Enabled? Basically the built-in administrative account (BIAA) will be treated like any other administrative account (such as the NDA). See the “Explain tab”.

So, if your devious mind is like mine you instantly wonder if changing it to Enabled means that since the NDA cannot access the drive and since the BIAA is being treated like the NDA now, does that mean that the BIAA cannot access the drive? The answer is that, sure enough, the BIAA account CANNOT access the drive when it is treated like any other admin account and UAC is on. Yeah! I have succeeded in making things worse!
What does it mean that the BIAA is treated like any other administrator? How does the UAC determine how they are treated? For that I draw your attention to the third UAC entry in the Local Security Policy – named “Behavior of the elevation prompt for administrators in Admin Approval Mode”. This is one of the areas where w08 and w08r2 differ in their implementation of UAC. W08r2 does not add any more entries into the Local Security Policy, instead it adds three more options to this entry and adds one more to the subsequent (“Behavior of the elevation prompt for standard users”). See the image below.

So there are multiple ways that administrators can interact with the UAC when it is turned on. But what if the UAC is turned off? That affects the eighth choice –“Run all administrators in Admin Approval Mode”. Per the Explain below, disabling this disables Admin Approval mode, and hence (I believe) the entire UAC.

W08 and W08r2 Admin Approval Mode settings results
Regardless of what level I set the Admin Approval Mode to (three in w08, six in w08r2), including “Elevate without prompting”, I was unable to open a subfolder or a root drive that had the perms I have been talking about using the NDA account when UAC is on. The prompts where the same – denial on root drives, prompting to grant perms to the NDA on subfolders.
Only when the UAC is off w08 has no problem enumerating the NDA’s membership in Domain Admins.
What does this all mean?
It seems to me the simplest solutions are:
- turn off the UAC
- do not use an NDA to access the server (the above is an issue with file/folder perms, but it might affect other aspects as well)
- do not rely on either Domain Admins for permissions. On second thought, do not rely on Domain Admins for ANYTHING.
Until this gets addressed by Msoft you are probably safest (ironically) in turning the UAC completely off on your w08 boxes. Not ideal, especially since the addition of “Prompt for consent for non-Windows binaries” helps remove some of the Clippy aspects of the UAC (see my thoughts on that here). Unfortunately the UAC has its tentacles in pretty much everything and who knows when this issue might trigger something more serious?
On a side note, some of you may be wondering why the UAC has that particular exception for the BIAA, especially as it is never turned off unless you do it via the Local Security policy. I cannot read the mind of the makers, but I suspect that it has to do with protection against elevated privileges. If you can restrict all NDAs (but not the BIAA) then if someone does hack your system on a regular user account and elevates themselves to an NDA they could STILL be restricted. It seems to me a logical way to guard against that.
Let me know what you think….
m
followup - http://www.myfriedmind.com/techBlog/2009/10/20/UACAndDomainAdminsPermissionsIssueOrPocketFullOfKryptonite.aspx