May 02, 2009
Using TS RemoteApp as an attack vector
So in today's session at SMBNation that I spoke at, I showed how to use TS RemoteApp with TS Gateway on SBS2008 to deliver remote applications through Remote Web Workplace. It is one of the most cool features in the Windows Server 2008 operating system. But we have to remember what its doing.
Part of the conversation we had was on the difference between local desktop display in TS RemoteApp vs just having a full desktop to the Terminal Server. One issue that came up was that as a RemoteApp, you can't run other applications.
Well, that is not actually true. If you think that, then a TS RemoteApp has the ability to be an attack vector for you. What do I mean? Well below is a screen shot of what happens if you hit CTRL-ALT-ENTER with the cursor focused on the RemoteApp window (in this case MS Paint running remotely):
At this point, you can run Task Manager.... then hit File->Run and run something else. In my case, I showed a few people afterwards how to start cmd and start exploring the network. Now, you will only have the privileges of the user account logged in as, but it is still something you have to be careful about. If you think a RemoteApp bundle prevents access to other application sor the network... you are wrong.
So is this bad? No. Is it really an attack vector? No. You just need to understand that when allowing ANY type of Terminal Services based access, you have to restrict the policies and access accordingly. No matter if its local or remote. Running a TS RemoteApp bundle of Office will display on the local desktop, but is STILL running on the Terminal Server. So it will be browsing the network the Terminal Server is connected to as the local net. It will also browse your own drives mapped via tsclient. So you have to remember that.
Hope thats useful. A TS RemoteApp bundle does NOT mean you won't have access to the TS desktop when displaying remotely on your personal desktop. And that's not a bad thing. TS Remote App is a convenient way to extend the workspace to your local machine, anywhere in the world. No pun intended. That's its power... and the benefit. Great remote productivity enhancement in Windows Server 2008. Use it. (Safely of course)Posted by SilverStr at May 2, 2009 10:37 AM | TrackBack