This article will give some information regarding the Copy & Paste functionality of Clientless RDP.
In regular RDP sessions you would (in Windows) work with Microsoft's Terminal Services Client. This client allows (when enabled) seamless access to your local clipboard. The Clientless RDP app is an application which works in your browser. From security points of view you do not want your browser to have constant access to your clipboard as this could be exploited.
From our own tests we are able to conclude that some browsers offer more support for clipboard integration to a web application then others. For example in Internet Explorer you will get a pop-up asking whether you want to allow access to the clipboard. In Firefox or Edge this pop-up is not shown. There might be settings that allow a web application access to the clipboard through the previously mentioned browsers, although we will not go into this in this article.
This article will show a method to transfer information from and to your Clientless RDP app when the browser does not offer access to the clipboard for the web application.
This "settings" pane has a Clipboard section. When you copy text in your Clientless RDP App the text will appear in the Clipboard section:
The text in the Clipboard section can be copied locally and pasted into the application where you need the text. To copy from the local machine to the Clientless RDP app you simply enter or paste the text into the Clipboard section:
You can now close the "settings" pane with the key combination Ctrl+Shift+Alt. After that you are able to paste the text placed into the Clientless RDP App.