Welcome to my challenge

The goal is to find a way to trigger the alert("You WIN");
An early hint: You do not have to bypass X-Frame-Options: DENY
There are no hidden parameters in chall.php

A working solution is known for the latest Firefox and Google Chrome version.

In case you found a solution write me a DM
https://twitter.com/insertScript


Solved by:
terjanq
shafigullin
_zulln
SecurityMB (unintended solution in Google Chrome)
RootEval
S1r1u5_
simps0n
D1r3Wolf_
lbherrera_
_nunohumberto
_bayotop
_fogfish_
l4wio