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.
Related
Let's say app.exe has been built with requireAdministrator manifest as detailed here (this is really needed for a reason that would be out of topic here). When launching the app, when Windows UAC is enabled, there is a normal prompt:
Now this application needs to run on Windows startup: in an Options dialog, there is a "Launch at Windows startup" checkbox that can be checked or not. When checked, it adds a key in the registry in
HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Run
to enable this "launch on Windows startup feature".
Problem: At Windows startup, when app.exe is (automatically) launched in background, there is this UAC dialog box (see screenshot before), which is annoying for the user.
Question: How to make that app.exe can be launched 1. with requireAdminstrator 2. silently at Windows startup ?
What is the clean way to do this? Lots of software do this (indexing software that both run on background since Windows startup, and don't show such a dialog box).
Note: I would like to avoid TaskScheduler method if possible: https://www.sevenforums.com/tutorials/11949-elevated-program-shortcut-without-uac-prompt-create.html
The indexing software "Everything" does show such a dlalog.
The others you are thinking of run only services with admin rights, not UI.
Running a service requires the software to be architected with that intent, ordinary user applications can be started with the service rules with the help of the "at" service, which you already know how to do (Task Scheduler).
You can substitute some other service for Task Scheduler, at the risk of annoying the user through needless duplication, waste of resources, and likely new security flaws.
Set aside your preference, and use Task Scheduler.
Or remove the background parts of your app and write a service to do those instead.
And be very careful when giving your code administrator rights. Any bug can result in subverting the entire security infrastructure. With great power comes great responsibility.
I have a console application written in c#, which downloads a file to program files. So of course it needs to run as admin. This program gets called from a Win32 C++ application which almost certainly is not running as administrator
What are my options. How can I get this to work on UAC and non UAC enabled boxes ( I don't know if there needs to be separate solution in each case )
Oh and the console app is in .NET 2.0
On a machine with UAC you need to include a manifest resource to specify that you want the process to run as administrator.
On a machine without UAC you will simply have to instruct your users that they need to run it as a user in the administrators group. Almost all users of XP (the version that you will most commonly encounter without UAC) are in the administrators group so you won't encounter many problems.
I never tried it, but this can probably be done using the
CreateProcessAsUser Function.
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).
This question already has answers here:
Disable Vista UAC per-application, or elevate privileges without prompt?
(3 answers)
Closed 9 years ago.
Is there a way to get my .exe file to execute with administrator rights instead of me
killing the LUA at registry or right click file and running as administrator?
When I alter the registry it prompts the user which I don't want. I am only adding the file to kill the LUA to give the user full rights to execute my .exe file.
If I can just get it to execute as administrator it would save me editing the registry. I can't find the source code for the application. It is coded in Delphi so it is a problem to add anything and the .reg file needs to be run with the .exe files on Windows Vista.
How can this issue be resolved?
You can't. If you could do it, any exe could to it and that would defeat the purpose of the UAC (assuming arguendo you believe there is a purpose for UAC). You can manifest your exe to require administrator privileges, but that will not stop the user prompt.
There are two proper ways to do this:
As already noted mark your exe as requiring elevated privilleges - the user will be prompted when starting your program, administrator privilleges and user confirmation are required.
Create a service running as LocalSystem that is allowed to do anything without prompting the user. In this case you have to implement interprocess communication mechanism for the service to communicate with user UI program, which may not be trivial. For this scenario your program has to be installed by administrator, but after that may be used by anyone - this is common for corporate scenarios.
Generally speaking Vista compatibility may not be easy to achieve and depending on your software may require a lot of work.
I'm not able to test this since I've only got XP with me at the moment...
Try creating a batch file with the runas command in it.
Note that the password will still need to be entered but it may save a couple steps.
If you just want to avoid the right-click and run as admin you can rename the exe to something like xyzSetup.exe.
There is (hopefully) no way that you can bypass the prompt, otherwise anyone can do it.
If you are just trying to avoid repeated prompts and don't mind being asked for the password or permission once, you could use runas with the /savecred option.
Generally this problem is solved by installing a Windows service which runs as SYSTEM or an administrator 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.
Install your service during the first run (or in the installer, which will require an UAC prompt).
I will have to read up on this but I don't have access to my source so this would be a problem.
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.