Why can all Domain Users seemingly launch the VMM 2012 R2 console and modify my VMs?

Posted on 2014-12-14
Medium Priority
Last Modified: 2014-12-26
Greetings -

Folks, I've run into something that is very concerning to me in my new VMM 2012 R2 environment.  I've found that seemingly any domain user in my domain can launch the VMM 2012 R2 console (if installed on their machine of course), and they can not only connect to the VMM server but also modify properties of my VMs, start/stop them, etc.  They can't connect to the console session but at any rate, this is highly concerning from an RBAC perspective.

The only built-in RBAC group in VMM that I can see is "Administrators".  The membership of this group contains all the defaults (i.e. the VMM server computer account, service account, default action account, Domain Admins, etc.)  It does *not* however contain any groups that would include Domain Users or any broad global/universal groups.

So why anyone can launch the console and play with my VMs, I have no idea.  Where else should I be looking for access rights?  Aside from my server administrators, I don't want anyone to be able to launch the console and connect, let alone make any setting changes or even see any VMs for that matter.

Ideas?  What am I missing about VMM 2012 R2 versus the old VMM 2008 R2 world where this was seemingly simpler or at least more secure/functional?

Thanks in advance.

Edit - Additional Information:

My VMM environment is extremely simple at this point as it is in the early stages of configuration.  Only a few hosts, about 20 VMs, a single private cloud, single domain, nothing extravagant.  It is VMM 2012 R2 (Update Rollup 4) running on a fully patched Server 2012 R2 box.
Question by:amendala
  • 4
  • 3
LVL 85

Expert Comment

by:David Johnson, CD, MVP
ID: 40499478
In SCVMM what group of users are administrators (as far as SCVMM is concerned)
LVL 24

Expert Comment

ID: 40500320
In VMM, click on Settings in the bottom left corner > expand Security > click User Roles > under User Roles in the right pane > click the Administrator user role > verify the members in this role in the bottom pane and remove members if necessary. If you have other custom roles then check the members for these roles also.

Author Comment

ID: 40500953
Good morning -

I actually answer the questions in both comments above in my original post but I'll answer again here.

There are *NO* additional individual members or groups in my Administrator role in SCVMM above and beyond the defaults.  The only members are as follows (with specific naming redacted for security):

DOMAIN\Domain Admins

And no, Domain Admins does not contain Domain Users, it contains only a small list of individual user accounts and no other groups.

This is what is so confusing to me.  VMM seems to be granting all Domain Users privileges when none above and beyond the action and service accounts, and domain admins, are explicitly configured.

Thank you.
Making Bulk Changes to Active Directory

Watch this video to see how easy it is to make mass changes to Active Directory from an external text file without using complicated scripts.


Accepted Solution

amendala earned 0 total points
ID: 40501407
I decided to create a role with "Read-Only" permissions that has access to no clouds or host groups and I added "Domain Users" as a member.

I've found that this restricts any users who are not explicitly part of a higher-permission RBAC group from making any changes or viewing anything.

This partially satisfies my goal but is so backwards that I feel as if something is wrong.

Firstly - it completely obliterates the concept of Least Possible Privilege by assuming everyone has all access until restricted.

Second - It violates the long-standing tenet in the Windows world that "Deny" permissions supersede "Allow" permissions.

Functionally, this solution does work.  If as a Domain Admin I open the console, because I'm part of a higher RBAC group, even though Domain Users (of which every Domain Admin is obviously a member) is in a read-only group, I am granted the permissions of the higher RBAC group.

The only thing this doesn't satisfy is why users are allowed to even connect to the VMM server AT ALL without being granted permissions.  As far as I'm concerned, unless explicitly granted permissions to an RBAC group in VMM, the console shouldn't even accept your connection or get past the splash screen.

Perhaps more on this later if I learn more but at this point, I think I've found my own solution.
LVL 24

Expert Comment

ID: 40501798
Sorry amendala, completely missed that bit in your original post. If what you said above is true then that is deeply concerning. I'm going to try and install SCVMM 2012 R2 on my machine and run it under my user account (as I use a separate account for admin tasks) and see if what you say is true.

Author Comment

ID: 40501870
By all means, I'd love to hear your results, let me know... I'll keep the question open.  If it restricts you, then I'm going to open a case with Premier Support to see if Microsoft has any good answers as to the behavior I'm seeing.

LVL 24

Expert Comment

ID: 40512424
Sorry amendala, haven't had time to install SCVMM 2012 R2 on my machine as of yet. I'll let you know how I go once I get a chance regardless.

Author Closing Comment

ID: 40518238
I have found no alternatives either here or anywhere else, including Microsoft, regarding this behavior.  The solution I devised is apparently the manner in which to configure SCVMM if you want the console locked down - at least in 2012 R2.

Featured Post

Making Bulk Changes to Active Directory

Watch this video to see how easy it is to make mass changes to Active Directory from an external text file without using complicated scripts.

Question has a verified solution.

Are you are experiencing a similar issue? Get a personalized answer when you ask a related question.

Have a better answer? Share it in a comment.

Join & Write a Comment

This article will explain How to fix Broken backup chain in Veeam Backup & Replication.
In this article, we will discuss how you can secure Active Directory using free tools, and how you can choose a safe and secure Active Directory security auditing tool.
In this Micro Tutorial viewers will learn how they can get their files copied out from their unbootable system without need to use recovery services. As an example non-bootable Windows 2012R2 installation is used which has boot problems.
This tutorial will walk an individual through the process of configuring their Windows Server 2012 domain controller to synchronize its time with a trusted, external resource. Use Google, Bing, or other preferred search engine to locate trusted NTP …

624 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question