Monitorr unauthenticated Remote Code Execution (RCE)

This module exploits an arbitrary file upload vulnerability and achieving an RCE in the Monitorr application.
Using a specially crafted request, custom PHP code can be uploaded and injected through endpoint upload.php because of missing input validation.
Any user privileges can exploit this vulnerability and it results in access to the underlying operating system with the same privileges
under which the web services run (typically user www-data).
Monitorr 1.7.6m, 1.7.7d and below are affected.