The Everest Toolkit WordPress plugin through 1.2.3 does not validate the type of files uploaded during demo-content import (the WordPress file-type test is disabled), allowing high-privilege users (Administrator by default, including non-super-admin site administrators on multisite) to upload executable PHP files to the uploads directory.
https://wpscan.com/vulnerability/f101071f-402a-40a2-bbdb-666512cd4049/