UAC Elevation vs. Impersonation - windows

(Skip to the bottom for the TLDR version.)
OK - so I have searched (really!) and all other UAC articles I have found seem to center on enabling, disabling, detecting or hiding UAC. My issue is not one of those, so here goes:
My user used to have the standard dual-token setup where I was in the Administrators group and the UAC's Consent UI would just ask me if I wanted to proceed. Now, we have separate administrative-level accounts that we need to use, and I have to authenticate with this new user. The problem I am having is that previously, starting an app as Administrator just elevated my current user, where now if I use the credentials of the new administrative user, whatever I am running runs AS that new user.
As an example, previously elevating CMD and typing whoami into the command prompt used to return my normal/current user, where it now returns the new administrative user.
This has serious negative consequences - since this is a new user, and an Administrative-level one, if any files are created using this new user, my normal user cannot write to or delete them unless I manually adjust permissions and ownership. If I use my development environment under the new account (e.g. I need to debug a service or work with a driver) and rebuild something, I end up with a bunch of files that I cannot manipulate unless I am an administrator. Likewise if I add a file while running as this new account - my SCM tool will not be able to update that file later unless it also runs under this new administrative account.
Also, Since a profile is associated with this user, things run under a completely different environment (different %USERNAME%, %USERPROFILE%, %LOCALAPPDATA%, etc.)
Installing an application will also work incorrectly if it is installed just for the current user (e.g. the "Just Me" option), instead of for all users. Things that are licensed to/in my normal user account also fail to function if run under the new account, because things are running as that new user.
The ripple effects of this change are getting larger and larger the more I work with it. So...
[TLDR] Is there a way to get temporary elevation of the current user without that user having the normal dual-token setup you get from being in the Administrative group? Or are you stuck with the impersonation behavior?

Related

Difference between User account with Admin rights and Run as Admin

I am running this in Windows 10
What is the difference between running a program in a user account with admin rights, versus running in a standard account but right clicking and running as admin - and by difference, I mean from the program's point of view.
I thought from the program's point of view, there would be no difference. But apparently that isn't exactly true.
See - I have this piece of hardware (The DLink Air Bridge for the Quest 2 Headset). It won't connect to the desktop app unless I run it in an account with admin rights. But here is the thing, if I run it in the same account (but now with only standard rights) but right click on the program and "Run as Admin" - it still won't connect. How can this be?
I am asking this here because the support for both Meta and Dlink is hopelessly, HILARIOUSLY inept.
Also - what is worse when it comes to security: Using an account for daily stuff with admin rights, or right clicking on particular programs that need it and always running as an admin. I assumed it was the latter - but I am an idiot when it comes to computer security.
When an administrator logs in, the full elevated token is stored in a system process and a more restricted token is generated from this and is used to start Explorer.exe at logon.
When this admin user elevates, UAC starts the new process with the full elevated token (often called "split token"). This causes some minor complications related to mapped network drives and HKCU COM objects but essentially the two tokens refer to the same user account and the same HKCU registry key.
On the other hand, when a non-admin UAC elevates they have to enter the credentials of an administrator and it is this administrator and their account/profile/HKCU that is tied to the token when the new process is started. Meaning, a process running as this administrator is present in the desktop session of the non-admin user. This means a different profile folder and different HKCU compared to other processes in the session.
According to Microsoft, UAC is not a security boundary. If you are really concerned about security then you need to log in as the administrator separately.

Lenovo laptops System update create admin accounts automatically

Lenovo's system update program can be started without administrator right. When the service starts, it creates a temporary administrator account to perform the installation.
Why can a windows application have right to create an administrator-level account? How can I achieve it when I want to create a similar program?
It's related to TVSU. A design point of TVSU is that even limited users can install updates from Lenovo. And to accomplish this, the TVSU service creates a temporary admin account with a randomized username and password, then uses it to do the installations on behalf of the limited user. This is the only time the account is created. The account is not created when an admin user does updates, because the admin user already has the permissions needed to do installations.
The account is supposed to be deleted after the TVSU session finishes, but I'm aware of a case where this doesn't happen and the account stays around. However there isn't any security risk to this because both the account and password are random and not known by anything except the specific TVSU process that created them, and this process ended the last time TVSU was closed. You can safely ignore the account, delete the account, or else it should be deleted the next time TVSU is run.

Active Directory two user with same permissions, one doesn't have permisions to give admin privileges

i've the following scenario:
In the company almost part of the computers works in domain. there is two admins with absolutely all permisions. Obviously, when a software is required in one of the computers one of the sysadmins must go to put his credentials and password.
So here starts the problem: with one of the admins everything works normally, but with the other user it's impossible. it says that the operation requires permissions elevation, and i insist that both users have exactly the same permissions.
Anyone have an idea what could be wrong?
thanks in advance
Let me see if I understand this. The first admin has no issues installing software, but the second admin does have issues (User Account Control Dialog box popping up). In what way have you determined they have the same permissions? Rather than answer that, just run through this checklist until you (or they) find the difference between their privileges and then correct it.
Compare the group memberships of their two accounts. One may be a Domain Admin, while the other might actually not be one, thus accounting for the UAC dialog box popping up.
If the above shows no differences, then compare a Resultant Set of Policy report between the both of them. This means when the first admin logs in, have him/her run this command: gpresult /H C:\Admin1.html
When the 2nd admin logs in, run a fresh report for him/her using gpresult /H C:\Admin2.html, then compare that to the first report, and act on any difference you see related to permissions:

How can I have better priviledges management in Azure roles?

AFAIK when I set up my Azure roles I have only one way to specify how much priviledges the process running role code will have - by using <Runtime executionContext> XML tag.
However this looks coarse grained. If I specify "elevated" my code runs under "Local system" which is unlimited priviledges and if I specify "limited" my code runs under some low priviledges user that doesn't have priviledges my code needs.
Is there some convenient way to run Azure role code under some custom user that has limited priviledges that I myself would control?
Right now, your code will already run as a limited user. In fact, there are no users on the VM - it is using a SID injection technique to get a security context at all. From your question, it seems like you need more than a normal user, but less than an admin?
If you really want to have different permissions, you need to create some users (use Startup tasks and net add or DirectoryServices) and set permissions. All of this is scriptable.
The more challenging part comes now to run your code as that user. For this, you need to do what is called impersonation. Your more privileged code (an admin process typically) can obtain a token for a local user and use that to impersonate a user. The code then runs as the user and is restricted. Impersonation is a well covered topic in .NET and other languages.
If you want a clever example of running code as another user, check this post by David Aiken:
http://www.davidaiken.com/2011/01/19/running-azure-startup-tasks-as-a-real-user/

Write to HKEY_LOCAL_MACHINE on Windows 7 without Administrator privilleges

First of all, I realize this is a messy situation, but it's not of my design, and I'm just trying to help, and for that I need your help.
App A is getting installed automatically via SMS installer under the Administrator account, not the PC owner's User account. App A has a registry key defined in HKEY_LOCAL_MACHINE hive.
After App A is installed, we want to edit the above mentioned registry key, to assign the User's C:\Users\USER_ID\Documents\ folder (I'm told we don't don't know who the user is and don't have access to USER_ID during step 1).
I know all about UAC, Application Manifest, and requestedExecutionLevel. However, I'm told we can't expect that all users will be in the Administrators group on their machine.
Solution must be backwards compatible with Windows XP as well.
I'm searching for options to get `C:\Users\USER_ID\Documents\' into the 'HKEY_LOCAL_MACHINE' hive under the above listed conditions.
I found this thread that might be related to a similar situation, but I don't fully understand it yet (so I will give credit to anyone that explain it better):
Find out (read) logged in user in a cmd started as a different user
I also read something that rules out ClickOnce:
Clickonce + HKEY_LOCAL_MACHINE
After App A is installed with admin privileges you are trying to run an additional script as the local user who does not have admin privileges . In order for your secondary script to write to the local machine key it will have to be run with administrative privileges ..period. That said, you have basically two choices:
1) Use the RunAs command to run the script with elevated privileges and have the user type in a admin username and password to run the script with elevated privileges.
2) This is the better way imo - Since SMS is being leveraged as the delivery tool, use its capability to detect and use local client configuration settings to write the key at the time of installation.
So basically the SMS package would have to be setup to run only when the local user logs on one time so that SMS can grab the current user and write it to a file somewhere.. after that is completed SMS can run a separate package as the admin (user will get prompted) to do the software install looking for the file containing the user and then consequently updating the local machine key to the correct user my document path.
Enjoy!

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