Web Patch 4

So, I'm guessing that the exploit is similar to the last basic. That much is clear but there are several ways to patch it. Can I add new lines, create a new function, etc? I'm really looking towards the right way to patch this so anyone needing help figuring out the exploit or anyone who has completed that, please contribute to this post.

You're not looking to add a new function; you're looking to augment an existing piece of code so that you can secure it better. The web patching challenges are cake if you're familiar with PHP. Just read through it and find the part that isn't sanitized correctly.