It's not just the user input that's the problem, but also the user's expectations.

What happens when a form asks you to "confirm" something, but the "cancel" button just doesn't work right?

Or when the form validates your email address with a regex that only accepts addresses from the 90s?

Or when the form's password input box is just a tiny little thing that you need to zoom in on just to type a single character in?

These are just a few examples of the form vulnerabilities we're going to explore today.

Subchapter 2: Form Vulnerabilities in Action