Menu Item Visibility Control <= 0.5 - Admin+ Arbitrary PHP Code Execution

Proof of Concept

1. As an admin, go to "Appearance -> Menus" and create a menu with some items of your choice.

2. In the "Menu structure" click on any item (the arrow down on the right of 'Page') and locate "Visibility logic" field.

3. Add the following code in the field: file_put_contents('/var/www/hacked.php', '<?php echo "failed"; ?>')

4. After saving changes and navigating to the menu's location, the visibility logic triggers executing our payload.