I need one of my .exe to always run as administrator without UAC prompt. My program will be installed with setup, which will have for one time admin rights, and I need to perform such step in this setup that my exe will be always executed as admin without UAC prompt.
I've found 2 solutions so far:
1.
Use custom service, which will elevate the program for me.
2.
Use Task Scheduler.
Is there any other solution? Some manifest probably?
Thanks.
If it were possible to do this, then UAC would be completely ineffective. The inability of applications to elevate themselves without user consent is the fundamental principle behind UAC.
Aside from already having an elevated process that launches it (i.e. service or task scheduler), the answer is no, it can't be done.
Of course what you are supposed to do if you want to just drive UI is to use the UI access flag in your manifest (see http://msdn.microsoft.com/en-us/library/ms742884.aspx). If you install your application in a trusted location (e.g. system32) and it is signed (bleh!) then when you run your application it will be elevated to high (for an admin account).
The signing requirement makes it slightly annoying but at least it reduces slightly the attack surface as your code gets run with high integrity but not with an administrator token.
Related
I am trying to run my c# exe as an system account. How can I do that. I've tried <requestedExecutionlevel level="requireAdministrator"> and <requestedExecutionlevel level="requireSystem"> The administrator is working but the second one is not working.
Please help me how can I do this.
To the best of my knowledge you can not force your app to run as SYSTEM. Either your app must be a service and the service is setup to run as System or you must use a tool like PsExec to launch your executable as system.
psexec.exe -i -s YourProgram.exe
When using requestedExecutionlevel the only 3 valid options are
requireAdministrator - prompt for UAC always (even if the user is not an administrator).
asInvoker - never prompt for UAC.
highestAvailable - prompt for UAC if the user is a member of the Administrators group but do not prompt and run as a normal user if the user is not a member of the group.
It's not directly possible. There are hacky ways if you are an administrator (like getting the security token from an already running service or something), but I far from recommend using those.
The point of the SYSTEM account is precisely that: that it's only run directly by the system.
If you want an easy-hacky-way without third-party tools (like psexec), you could set up a ONEEVENT scheduled task (with schtasks, which is part of the OS), which can indeed run with the system account. This would still need two processes (although it could be the same exe with different command line parameters for the task and for setting it up), but it'd work.
I've been wrestling with this issue for a few days and can't find any posts that solve it for me. Maybe what I want isn't possible.
We have developed a WinForms application for internal use at our company.
Most employees do not have admin access in windows.
Our application requires admin access to the machine and needs to automatically start when the user logs on.
Here's what I've tried:
1) Putting a Shortcut in the Startup folder
I can get the app to automatically launch (using a relauncher), but it still requires an admin to be at the computer on every restart (to enter the password).
2) Registry Key
I created a Software\Microsoft\Windows\CurrentVersion\Run registry key to automatically start the application. Whether I run the relauncher or the app itself, UAC demands a password on every restart (or relogin).
3) Scheduled Task
I created a scheduled task to automatically start the app on logon using admin permissions on the machine (under use the following account). I also checked the 'Run with highest privileges' box. UAC still pops up on every restart.
4) Windows Service
I tried to run the app as a windows service, but it has a user interface (which is disabled by windows services).
5) Disable UAC for Specific Program
It looks like you can disable UAC for a specific program but that involves downloading the Application Compatibility Toolkit, creating some kind of database, etc. I'd very much prefer that our IT staff wouldn't have to do that at every machine. At this point, it's probably my only option.
It seems like an admin should be able to install an application so that it runs automatically without a prompt. Am I missing a way to do this?
You should make split your program into a non-admin UI, which runs on user startup, and an admin service, which performs the administrative tasks.
To run admin-requiring code from the UI, use WCF to ask the service to do it.
Beware that hostile parties may impersonate the UI and ask the service to do malicious things; you need to carefully figure out what the service should be able to do in response to IPC calls.
Your problem is not a UAC problem, it is a security problem.
And the answer depends on what your application that "requires admin rights" needs to do.
If your application needs to be able to start, and stop services, then the User needs the ability to start and stop services. In which case you need to give the users that privilege.
If the user's need the ability to alter or delete files, then they need that privilege too. In that case it is easier to grant Full Control permissions to Everyone.
If your application needs the ability to modify registry keys in the HKLM tree then you can, again, grant Full Control to Everyone in the registry.
If you need your users to have the ability to modify items, then they need permissions to modify those locations. Granting them those NTFS permissions is not a bad thing; it is exactly what those permissions exist for - to control access.
But why
But then we ask why? What is it you're doing that users need all the rights of an administrator, and all capabilities of an administrator, all the power of an administrator, but you don't want to make them a member of the Administrator's group?
The answer is almost invariably that your internal use application doesn't need to run as an administrator.
What Would XP Do?
The question becomes:
What would you do on Windows XP?
A standard user on Windows XP didn't even have the UAC convenience feature. If a user wanted to run an application an administrator: they had to logout and login as an administrator. How did, or how would, the application work on a system with UAC disabled?
Presumably very little of your application needs to run as admin - the rest would be better running as the unprivileged user. This is very common (think self-updating browsers, for example).
The proper way to do this is to install a service to do the privileged bit, and have the UI communicate with the service.
Our application requires admin access to the machine ...
Why?
You cannot bypass the UAC prompt, and this is by design.
See FAQ: Why can’t I bypass the UAC prompt? for a good discussion of why. Excerpt:
If it were possible to mark an application to run with silently-elevated privileges, what would become of all those apps out there with LUA bugs? Answer: they'd all be marked to silently elevate. How would future software for Windows be written? Answer: To silently elevate. Nobody would actually fix their apps, and end-user applications will continue to require and run with full administrative permissions unnecessarily.
I have a C# app that needs to allow the user to change the Computer Name. This is a pretty privileged operation. I can only get it to work if the user runs the app as Administrator (Windows 7, right-click on executable, "Run as Administrator"). Fine, but the user IS an administrator, so why would they need to Run AS an Administrator? I've tried this several times. It always fails if the user--an administrator--tries to do it running the application normally. It always works if they run it as "Run as Administrator".
If the answer is, "It just works that way, you have to run as admin even if you are an admin," my question is how can I detect if they are running with super-duper admin privileges? I found this, but it just checks to see if the user is part of the Administrator user group which, I already pointed out, isn't sufficient (and throws a null pointer exception).
Am I missing something here? Do I need to approach it from another angle?
It's because of User Account Control (UAC). Introduced in Vista, this changes the way administrator user accounts operate.
When an user from the administrator group logs on, the user is allocated two tokens: a token with all privileges, and a token with reduced privileges. When that user creates a new process, the process is by default handed the reduced privilege token. So, although the user has administrator rights, she does not exercise them by default. This is a "Good Thing"™.
To exercise those rights the user must start the process with elevated rights. For example, by using the "Run as administrator" verb. When she does this, the full token is handed to the new process and the full range of rights can be exercised.
You almost certainly don't want to be detecting whether or not your process is running elevated. Best practise is to mark those parts of your program that require elevation and force the system to show UAC elevation dialogs when those parts of the program execute.
The bind is that elevation can only happen at process start. So if you need to split your app into parts that require elevation, and parts that don't, there need to be multiple processes. Whilst you could mark your entire app as requiring elevation, you should not do so if the only thing that needs elevation is the very rare scenario where the computer name is to be changed.
Your next step is to bone up on the details over at MSDN. For example:
http://msdn.microsoft.com/en-us/library/windows/desktop/bb756996.aspx
http://msdn.microsoft.com/en-us/library/windows/desktop/aa511445.aspx
We are about to roll out several hundred new machines running windows 7, with the OS installed via WDS so at the moment we can make changes and sysprep them into the build.
The problem is a .Net app we wrote years ago which itself spawns a modified command shell. That shell runs a dataflex application that itself needs to run with elevated permissions.
We don't grant users any general admin rights.
Is there a mechanism where we can pre-allow our .Net app to run as administrator so that the command control runs as Administrator?
I'm aware of the changes I can make in the app.manifest to require that the program runs as Administrator. I'm not aware of how I can (as an Administrator) configure the machine to allow that to happen without giving the user more rights or credentials than I would want them to have.
Does the application have to run as Administrator, or does it just need access to specific things? If it has a spurious "am I admin" check at startup, you can probably use a shim from the Application Compatibility Toolkit to lie to it, and then configure access permissions to the things that it actually needs.
If that looks like it'll fly, then you'd be better off taking further questions over to serverfault.
What Roger is getting at is that many people assume that if an app doesn't work as a normal user, they have to give it Administrator rights.That's not true in many, if not most cases. You have to find out WHAT specific rights it's failing with, and then assign those rights. This is more work, but it avoids giving general administrator rights to people.
Background: I am by no means a windows security / user permissions expert. I have an application (written in C#), that has to be able to write / delete files & folders in its root directory, write / delete files elsewhere on the disk, write/modify values in System Registry (Local Machine) and start & stop other applications and services. I figure that I need administrator privileges for at least some of those actions.
I tried running this and on computers with UAC turned off it works great without any additional settings. However on computers with UAC turned on (any level above 'never notify' in Windows 7) it will crash. I need it to work on all computers.
Up to now I would just manually check the "run this program as administrator" checkbox and everything would be fine. However now we have decided that we will allow customers to install this software on their own, and it needs to run "out of the box".
I have a deployment project in Visual Studio 2008 that installs everything and writes the necessary start up data in registry. What I need to do now is to set the "Run this program as Administrator" flag. I am guessing this isn't quite as simple as I'd like it to be.
So What is the proper way of doing this? This program is started on startup, and it would be irritating for our customers if UAC would pop up (and possibly dim the screen) every time they restart their computer.
Thank you for your help.
EDIT: Thank you for your replies. I realise that working around UAC would be frowned upon, and I can see that Microsoft does not support "white lists" so it would ask for permission only once. That's fine I can respect that, however I do have some follow up questions:
Can you provide me with a link that will show me how to properly elevate the program to correct elevated state? Is there any literature on what are the options, etc... Basicly I'd love a UAC 101 guide.
Is there a way to elevate the security status when I need the extra privileges (and only then prompt with UAC). Basicly this applications runs in the background, doing mostly nothing for most of the time. Every now and again it will check some files (at this point I will require to be able to write to disk and read the registry (read only is fine at this point), however since it's a temporary folder it wouldn't matter where I'd put it. If there is a location where the application can write without any privileges that would be perfect.)
However at some point I will need to preform all the rest of the tasks (user needs to confirm this action anyway) so if UAC would prompt at this point that would be no problem. Is there a way to elevate it just at this point, and then return it to default permissions?
Will such a solution work with older versions of Windows, including Vista and Xp (and perhaps older?) What would it take to make it work?
The proper way is to elevate when the program starts, with the UAC prompt (which you can set via the program's manifest) - attempting to be clever and bypass it is frowned upon.
Think about it - if you could install something which would elevate automatically without the UAC prompt ... what would be the point of UAC?
To add a UAC manifest to a program you simply add the manifest in a project and edit it. A sample manifest for UAC is here. If you want to elevate at the last possible moment then you need a spawn separate process - you cannot elevate an existing process. So separate that bit out and then start it using
Process.StartInfo.UseShellExecute = true;
Process.StartInfo.Verb = "runas";
You need to rethink how your application works. You're quite correct that it would be annoying to display an elevation prompt on login. So don't do it. On the other hand, you may well have tasks which you need to perform using administrative access.
So you have two choices:
Change your tasks so that they no longer require administrative elevation (e.g., write your files elsewhere).
Break your application into a Windows service component and a user interface component. The service component can run under an elevated account (hopefully the least-elevated account necessary to perform the tasks you need to do). The user interface component can talk to the service (via named pipes or similar) when necessary.
You can split your program into two components:
a user application running without elevation
a Windows service that is responsible for the tasks that require elevation
Since you're using .NET, communication between the components is probably easiest done using WCF.
And as a side note: Programmatically modifying files under C:\Program Files is not considered good practice and might lead to a number of other problems. Windows has dedicated places for storing configuration settings and other program data.