CJ File Browser add-on for TinyMCE 4
CJ File Browser is a file management system to allow you to view and modify a server's directory contents through the use of a web browser. It can be implemented as a plug-in with tinyMCE or work separately in standalone mode. With it you will be able to upload any file type (including images) as well as a limited ability to modify directories. Some of the actions you can perform are: upload files, delete files, navigate directories, create directories, delete directories and if the file is a supported web image (GIF, JPG or PNG) you will be able to see a small preview of the image.
Get more info on CJ File Browser home page: https://cjboco.com