In Kooboo CMS 2.1.1.0, it is possible to upload a remote shell (e.g., aspx) to the server and then call upon it to receive a reverse shell from the victim server. The files are uploaded to /Content/Template/root/reverse-shell.aspx and can be simply triggered by browsing that URL.

Kooboo CMS 2.1.1.0 is vulnerable to Insecure file upload. It is possible to upload any file extension to the server. The server does not verify the extension of the file and the tester was able to upload an aspx to the server.