I have an app that normal users need to be able to run, but requires administrator privileges to actually function.
I tried to make the shortcut that my users run it with "Run as administrator" but this just causes a UAC prompt whenever they try to run the app.
Is there any way to elevate privileges programatically, without my users needing to go through a UAC prompt and/or knowing an administrator password? From a security standpoint, I understand that most applications shouldn't be allowed to do this, so I'm hoping there is some way to do it if I can provide a valid username/password pair, or something.
The app is written in C#, so a fully managed solution would be preferred, but p/Invoke Black Magic (or even writing an MC++ Wrapper Which We Do Not Speak About) would be more acceptable than disabling UAC entirely.
Generally this problem solved by installing a Windows Service which runs as SYSTEM or an admin account. Then your application can request the privileged action from this service.
Obviously to not pose a security threat ensure that your service can't run arbitrary code or something which might leave the all users vulnerable to privilege escalation attacks.
Winpcap and most of the other sniffing applications use a similar design to give sniffing access to unprivileged users.
Actually, why don't you just create a Task Schedule which runs the app with elevated privileges? As long as you setup the Task under elevation, it will not prompts you for a UAC when it is auto-run during reboot or whatever your trigger is.
Just make sure you set level=requireElevation in your manifest file, and task scheduler will run your app with admin rights without prompting your user for admin rights, as this had already been established when you setup the task with admin privileges.
It's not possible. You cannot decide to suppress UAC prompt.
You have to ask yourself:
What would happen on Windows XP?
The user is a standard user on Windows XP, and the application "needs" to run as an administrator. Are you:
going to refuse to run?
going to crash on startup?
going to show the user access denied error messages?
If the user is simply not allowed to run the application as a standard user on Windows XP, then UAC is your friend: it tells the user that they have to be an administrator.
And it even offers to let them (temporarily) gain administrative privileges.
But you have to ask yourself:
What would happen on Windows Vista?
In order to elevate, the user will need someone from IT to walk from three buildings over, so they can type in their credentials "over the shoulder". Perhaps you can make the user's life easier. Let 99.9% of the application run, and split off that 0.01% to an "administrative" module.
Related
I'm trying to use SetSystemTime (from Kernel32.dll) or alternatively to use TIME from cmd.exe.
Both fail, TIME gives me the error
A required privilege is not held by the client.
I've already used gpedit.msc to add local/Users and also the user itself to security settings/Local Policies/Change the system time.
I tried to enable the privileg with AdjustTokenPrivileges( SeSystemtimePrivilege ...), but I got a GrandPrivilege failed error .
I'm using Win7 x32 Professional.
It's a standard user with admin privileges, but I'm trying to make the time changes without "Run as Administrator", as the program that calls the SetSystemTime function shouldn't be started with "Run as Administrator".
I supposed that the purpose of the Change the system time policy is exactly for this case and it's also described at MSDN
I'm at a loss what to do.
It turns out that although SeSystemTimePrivilege doesn't trigger UAC for a non-administrator, it is still removed from the restricted token that is generated when an administrator logs in. The upshot is that you can use group policy to assign SeSystemTimePrivilege to non-administrative users, but the policy has no effect for an administrative user.
If it is acceptable for the program to require elevation when run by an administrative user, you could use the highestAvailable manifest setting. That way, the program will only ask for elevation if the user is an administrator. Alternatively, you could design the program to ask for elevation only when it actually needs to set the time.
If an elevation prompt is not acceptable, you will have to install a system service to change the system time on your application's behalf.
I want to create PSSession on remote machine with administrative rights,anyone knows how to do that.
I have notices even i know administrative credentials, and using same while creating a PSSession, don't let me execute some commands on that remote machine.
I have searched, and found even using administrator credentials at PSSession don't create my session as administrator.
any idea how to do that or even how to switch session?
This is a very good question.
Your problem, as you probably know, is caused by having UAC turned on, on the remote machine. This means, that even though you are running PowerShell session as user who is a member of the Administrators group, your PowerShell session is not executed with elevated privileges.
If you execute a script localy on the server, there is a way to automatically elevate privileges within the script. This is explained here.
A self elevating PowerShell script
Unfortunately for you, this still creates a popup prompt for user to accept the privilege elevation. This makes it completely useless for remote execution.
I know that a lot of people will probably disagree, but the best (and possibly only) solution is to turn UAC off on the target machine.
Firstly I want to emphasize that I'm not trying to do anything "nasty" or "hackerish", nor am I trying to hide anything from user here.
During installations (using InstallShield LE) of my application user is prompted by Windows UAC to allow it to run in Administrator mode; If user accepts it - installation continues (standard behavior) and user again can check the option to add this program to autorun list (by adding a registry key to HKLM/../Run). All is fine and normal. But after every Windows restart, when this application starts, UAC kicks in and asks for user permission. Question is, how to avoid it, since it's a bit annoying (yet my app needs Administrator privileges to run)?
I mean user already granted such permissions on installation, so I cannot see a reason why it needs to be prompted on every startup? Moreover, I believe most antivirus software and such, also require elevated permissions to operate, but UAC doesn't prompt for it at Windows Startup.
Thank you for any advises, information, comments or solutions.
Does your application really need to start elevated? Or will it need to elevated access later when the user uses it to perform an action? If you can, drop the later admin task into a separate exe, allowing the main exe to start with no elevation - when you shellexecute the worker process later it will UAC on demand.
At install time, as you have noted, you have elevated the installer. If you want to run elevated code on subsequent runs, automatically, this is the point to install a service - which is what all those other apps you mentioned do.
You can't get around UAC for a process started in an interactive session. You could use a service running as a privileged user but you would be far better off finding a way to do whatever you do without requiring admin rights.
It's not possible for a program to run elevated without prompting. What you want to do is factor those portions of your application that need elevation into a windows service that runs as system. Then your autostarting application can make remoting calls to the service to delgate those activities that the user can't do without elevating.
Not done it but I found this article Selectively disable UAC for your trusted Vista applications that says use 'Application Compatibility Toolkit' from microsoft.
The Compatibility Administrator allows you to create a database of
compatibility fixes that will allow you to run certain applications
without an accompanying UAC.
Run the Compatibility Administrator as admin
select a new database template
Click the Fix button on the toolbar. When you see the Create New Application Fix wizard ... enter details about your app
Select a Compatibility Level
Select RunAsInvoker as the fix
It seems that the last one
Selecting the RunAsInvoker option will allow the application to launch
without requiring the UAC prompt.
Should do what you want provided that the invoker is admin and I think you can do this at start up using the scheduler : Create Administrator Mode Shortcuts Without UAC Prompts in Windows 7 or Vista
As you can see it runs your app in the compatibility mode which may or may not be acceptable for you.
I need to change the behavior of my application depending on user privileges:
When my application can run as Administrator
When my application has limited privileges
Since "requireAdministrator" is embedded within the manifest, the same .exe can't work on (1) and (2) at the same time.
What's the best way to deal with this issue? I am planning to pack two executables (one with "requireAdministrator") and decide which one to run.
Someone have other suggestions?
You can use a manifest that asks for highestAvailable instead of requireAdministrator or asInvoker. This will elevate if a person who can just consent to elevating is running it, but won't if it's someone who would need the OTS prompt and entering an admin id and password. I don't care for it myself, since you can't write your code in confidence knowing whether you have the privileges or not. But this is how to achieve what you're asking for.
I'm marking this as a community wiki because I'm not really looking for one complete answer. So if you feel like posting one or two things that will activate the UAC prompt instead of a comprehensive list then go ahead.
What actions in Windows will activate UAC? I'd like to avoid it as much as possible because my application doesn't need admin privileges. And I'm sure many other people want to avoid it.
Specifically, I would like to know if reading from the registry would activate it. Or writing to it?
You don't need to address the above question, just anything that will activate it is fair game.
It's really hard to Google anything about UAC because you get bombarded with articles about how to disable it. And I'd rather not have my application make the assumption UAC is disabled.
Nothing "activates" UAC.
If your application would fail to run as a standard user under Windows XP it will fail to run under Windows Vista or Windows 7 as a standard user.
What you are really asking is: what actions can a standard user not perform under Windows?
The things a standard user cannot do are pretty well known (they've been the same since Windows 2000). The main ones are:
modify anything in HKEY_LOCAL_MACHINE
modify anything in the Windows directory
modify anything in the Program Files folder
If you try to do any of those they will fail on:
Windows 2000
Windows XP
Windows Vista
Windows 7
Nobody should have been running as an administrator for day-to-day computer use. If your application did any of those bad things in Windows XP it would fail. The user would have to:
logon (or fast user switch) to an administrator
perform the administrative task
switch back to their real account
UAC is a convience mechanism, allowing you to easily temporarily switch to an administrator. Nothing you do will "trigger" it; you have to make it happen.
If you know your code needs to modify a file in C:\Program Files\My App\Data, then you should add a button on your form that will trigger the elevation.
You then need to launch an (elevated) copy of your program, do the thing, and close.
I created a launch4j installer (an exe-wrapper for java programs) and named it "MyApp.exe". It doesn't need any admin authentication. It just runs fine without any UAC prompt.
BUT: If I rename this installer to "install.exe" or "setup.exe", the UAC icon appears and I get a UAC promp when starting the installer.
Seems as if there are some "reserved words" in filenames that cause windows to start a program with elevated rights (UAC).