I've recently discovered an oversight in a popular games config file system that allows the users to use an item even if you haven't yet unlocked it. This is a multiplayer game where players are to reach a level where they will then be able to use said item. The 'exploit' works by adding an entry to an INI file format with the ID of the restricted item.
My plan is to develop and sell a tool that will give players the ability to unlock the aforementioned items. I would like to know if this is legal to do.