If the librarian is "vulnerable," they won't realize you've added a second, unauthorized command. They will return with a stack of gardening books, but sitting right on top will be a slip of paper with a name from the payroll. How to Stay Safe
If you are seeing this on your own website logs or search bar, it means someone (or an automated bot) is testing your site for security holes. To prevent this: If the librarian is "vulnerable," they won't realize
The librarian goes to the back (the database), finds the gardening books, and brings them to you. If the librarian is "vulnerable
To understand how this works in "real life," imagine you are at a library: finds the gardening books