Aministartor Rights for a set of code - passwords

Good day.
I am developing a program that will be used in a corporate environment by the end users. The application will automatically fix certain errors as soon as the user selects the application name, chooses the symptom or error message and clicking on the fix button.
The idea behind is to decrease the amount of calls we receive at the IT Service Desk (The company's personal Call Centre for IT Issues) and at the same time assist the end user by resolving the issue within a minute (versus waiting on the phone for up to 15 minutes or more).
I've am not yet allowed to upload an image of the application, but imagine a small'ish windows form with 2 columns; Aplication name and Synptom. The user will choose the application's name, click on the error message and click on the FIX button. This basically automates whatever we has IT Techs would manually.
The problem I'm facing is that some of the code is supposed to be executed with adminsitartor rights, eg. Stop and Start a given service, adding regsitry entries for Local Machine, etc.
Given the fact that none of the users will be allowed to have elevated rights and the fact that they need to use this application as a sort of "self-help" alternative without the need to call the IT Service Desk, is there a way to give a set of code "administrator permissions"? The application should NOT request the user to enter ANY passwords.
Regards,
Willem


No way, AFAIK: the model in common operating systems is process-centric, so that the process is given permissions that are then inherited by its code. You can elevate such privileges at some point, but that will be for the whole future life of the process (or as long as the authentication token for it ceases to be valid).
In windows the right way to do that is to employ a back-end service: at boot, you start the service called IT_Auto_Fixer_Back_End with high permissions (try to avoid Administrator, NetworkService or LocalService could be enough for you). When the app IT_Auto_Fixer_Front_End is started with USER privileges, it operates until it needs something with high privileges. At that point it sends a request to the service, that will do it.
If you choose this way, some important advices:
The IT_Auto_Fixer_Back_End must not become a backdoor! If you use TCP as form of communication with IT_Auto_Fixer_Front_End, make it listen localhost only and use SSL (yes!) to encrypt local traffic
It must not be possible to invoke arbitrary commands using IT_Auto_Fixer_Back_End. You need to enumerate the possible requests that could be made (i.e. a command like stop_mysql_service rather than accepting directly the string net stop mysql - the application logic will translate your string into the real OS command)
Every input from the user could be used to perform command injection. To prevent this, use the Windows API that requires an array for the command - this way if the user adds options to a command (i.e. the name of the service in net stop) they won't be interpreted as another command (common scenario: when accepting the name of the service as a parameter, a malicious user that tries to execute something like net start mysql ; net user /add hacker t00E4sy). Authentication and encryption will not help you against this, you must escape any user input that goes inside the command.
Sanitize your ENVIRONMENT by using the API that executes commands setting the PATH (and other relevant variables), so that the user will not be able to taint the PATH, executing C:\temp\net.exe instead of C:\Windows\System32\Net.exe
IT_Auto_Fixer_Back_End service should be authenticated: it should check every time if the request comes form the user by checking if the Kerberos token is valid (Windows => you get a very nice Kerberos environment for free!). This will prevent someone else to break into the machine, use SSL to connect to the localhost port and elevate privileges through your service
The above (authentication) still stands when something else (i.e. shared memory, windows sockets, a file, etc...) is used as communication channel between IT_Auto_Fixer_Back_End and IT_Auto_Fixer_Front_End
Life gets harder when you want to properly implement something dealing with multiple level of permissions...

Related

HCL Domino Remote Console: How to get name of user connected remotely

I would like to restrict some functions in a user written server add-in for certain users or groups.
Question: Is it possible to get (via an API) the user name who is sending a "Tell" command from a remotely connected server console?
Example:
Tell AddinName Command (issued remotely by Hotline User)
Tell AddinName Command (issued remotely by Admin User)
The remote console (and therefore the "Tell" command) is available to both users, but a subset of commands should only be allowed to authorised users (e.g. Group in Server Document->Security).
Is the user name (entering the "Tell" command) available (e.g. in the MessageQueue)?
I know that internally in Domino there are already some restriction possible to commands issued at the console.
The session.getCommonUserName() always returns the server name (since the add-in runs in context of the server).
Thanks for any pointer or ideas.
Andy

I believe that the answer to this is no, and it would not be advisable to implement tell commands that you can't trust to all authorized administrators.
If you really do need to confirm a user identity for a command, you're going to need to use database to queue the commands. I.e., you could build an application that stores the commands in documents in a database with a restricted ACL. Your addin code can use an Extension Manager hook to monitor the database for changes and read new documents when they appear, or you could have your application use NotesSession.SendConsoleCommand to issue something like 'tell myAddIn process ' to wake up your addin and give it the noteid of the document it just created. If you need to protect against people with full access admin rights overriding the ACL, your application could digitally sign the documents and your addin could verify the signatures.

Mac terminal restriction

I'm building a web API that use a command line on the server.
This command do certain build tasks and it has many optional arguments
I'm not so happy about building a rest API to handle all the arguments and escape/validate all security risk there is...
Is there anyway you could instead whitelist only one command to run by a certain proccess/program or user?
Or can it be as easy as validateing the command if it contains ; if it dose > consider it as unsafe to run?
Or can you create a little sandbox?

You could create a user (login account) on your server that runs your whitelisted command instead of a regular shell when he logs in, if that's what you mean.
For example, I have worked at some sites where there is a user account called "reset" and another called "mountall". So, if you know the password of that account, when you log in, certain databases get reset and you get logged out, or all filesystems in /etc/fstab get mounted and then you get logged out.

Run Process From Different User, Without Password, but from Admin (VB.NET)

I need to monitor other accounts on a Windows Server, and have figured out that to do so, I have to be able to run a monitoring process on them. The main program runs from a full-access (possibly NT_AUTHORITY) account, but all ways of starting processes seem to require the user password! help please!

You could create this as a service instead and when installed supply password for the service properties (which user you want to run it as). Then the need to re-enter password should disappear.

Logoff script to change user

Using Windows 2003, I'm look for a way to create a "logoff script" that will continue with the current logoff then immediately login another user. So, "UserA" logs off. Script fires to login "UserB".
This is part of an application upgrade for a computer where we have written the 'shell'; similar to a kiosk application. For the upgrade we need to logon as 'Adminstrator' then, when the upgrade has completed, logoff 'Administrator' and logon as 'sample_user'. We would like to accomplish this WITHOUT rebooting.
Note, I do not want a script that will initiate the logoff (i.e. "shutdown"). I'm looking for a script that will run upon the user logging off (set via Group Policies). As above, the script should log a different user on.
Thanks.

Don't think it's possible in the stated way (script at logoff).
You'd have to set the machine to logon automatically as a specified account and then log off (having it log on automatically for you) and then you'd have to disable that feature again afterwards, by placing a temporary logon script... generally sounds messy.
The actual setting can be made using tools like Microsofts Shared Computer Toolkit or similar (not so sure how the "normal" registry auto-login behaves at manual logout but I've had an XP kiosk that would automatically log on instantly, even if you logged out manually - you had to override it using some key like shift+logoff to be able to manually specify the login again, so somehow it can be made).
The "easiest" way might be to replace msgina.dll with someone of your own making...
But why are you doing this? Just use runas and start whatever you need to do as that other user without logging off the console user - it's a multi-user system afterall? The desktop is just fluff ^^
(This will anyhow require that the user credentials are available to your script, which kind of makes it redundant as you compromise the security of that account - defying the purpose of having that second account in the first place, for whatever purpose it exists?)

I would try setting the registry to autologon with the user you want, and then simply logging off the admin user. That should log your kiosk-user right back on.

Not sure how to login another user once the current user logs off (not sure if windows would let you...)
But you can use shutdown to logoff:
shutdown /?

Here's some ideas that probaly fall into the "cheap hack" category:
How about logging in at UserB in the first place, and then using runas /user:userA <cmd> to run the first part of the install process?
If that's unacceptable, I know there's a way to make Windows workstations (those that aren't part of a Domain) automatically log in into a certain user account after a restart. Perhaps if you looked into which Registry changes happen, and duplicated them, a reboot would automatically log in that user. (Of course, as a final stage, after userB logs in, you would have to revert those changes :-)
It also occurs to me to wonder if perhaps there's a way for a service to force an open "login screen" to log in as a certain user. Maybe using some method like the way the Remote Desktop does it remotely... If that's possible, then you could create a service that you install before logoff of userA, that would trigger the login of userB.

You can script it with VNC (there are many free versions, take your pick). Set up a VNC server process on the machine to listen on localhost. When the user logs off, your logoff script will connect to the machine using VNC and send the keystrokes necessary to log on the next user. VNC uses the RFB (remote framebuffer) protocol; there are libraries for most popular languages, so you should be able to get something working quickly. Or there are related tools that might help.

If you were to run something like this as a normal script in a given language, it would most likely not work as when you log out of your account, all processes should be killed along with your running script.
You might be able to create some sort of 'service' that would run on a service account (i.e. always active) that would automatically do this user switching for you.
My bets are on Windows Powershell, although I'm not entirely sure what functionality it has as far as actually creating a service.
A quick search brings up the following (The second link is to a forum but it mentions running Powershell as a service and sending that service a parameter which would be the path to your user switching script)
How to Create a Windows Service using Powershel
Powershell Script as a Windows Service

I don't have a Windows 2003 server or a system with a "Group Policies" setup to test my hunch but you could take a look at SU ("switch user") for Windows. Originally part of the Resource Toolkit this has been extended to a new SUperior SU. Do post the results/script if this works.

You could approach this from the perspective of building a remote control utility (like VNC, etc). The big thing here is that if you want access to the Logon screen (i.e. the CTRL + ALT + DEL / username/password) part, the only kicker is that a Windows Service is the only component that can access this, so you'd have to create one.
The only problem I see with this technique as a whole is that even if you spent a great deal of effort getting it to work (and it would be a pretty big effort), the chances of this working successfully with the whole thing originating from a logoff script (i.e. when stuff is shutting down) are low even due to the number of things that can go wrong when logging back on as Administrator.
Just remember that for anything you need to run as an Administrator, there are easier ways in Windows to make that happen (such as Run As, changing the user permissions on the items that need to update, etc).

Terminal Services: Get Client Name While Running As Administrator

Under normal circumstances, a VB.NET application of mine can check the ClientName environmental variable to get the name of the workstation the user is connecting from.
So when WorkstationX RDPs into ServerA:
ComputerName=ServerA
ClientName=WorkstationX
That works fine.
If I right-click on the application and choose Run As Administrator, the ClientName variable is not set.
Does anyone know of a way of easily getting the workstation name of the client connected to the terminal server, even when the application is launched via "Run As Administrator"?

If you don't want to deal with the P/Invoke business yourself, you can use Cassia, which wraps it for you:
New Cassia.TerminalServicesManager().CurrentSession.ClientName

The terminal services API might be your answer. I use it in a VB.NET app to log off user sessions on a given server, and to retrieve the names of the workstations connected to those sessions. The code I have has a lot of p-invoke stuff and is rather unwieldy, but I can post it if you want.