For this challenge we have a Google Forms link. After the first page, we get to a page that redirects to itself when answered.


We are getting nowhere like this, so we can check the page source code, Most of it is irrelevant, but one hidden input is very interesting:

`<input type="hidden" name="pageHistory" value="0,1,1,1">`

Seems like Google Forms stores the user's page history in a hidden input element. Our goal is to get out of the infinite loop, so I will modify this history like this:

`<input type="hidden" name="pageHistory" value="0,1,2,1">`

If I press back on the form, it should redirect me to page 2 of the form. And as such half of the flag is revealed. Clicking Submit reveals the rest of the flag



Flag: **lactf{l34k1ng_4h3_f04mz_s3cr3tz}**