Web security

Open-redirect detector

We fetch the URL you give us, extract every internal link, find the ones with redirect-shaped query parameters (?next=, ?return=, ?redirect=, …) and probe each one with an attacker-controlled value. Fails are endpoints that honored the destination without checking.

We crawl one page and probe up to 25 redirect-shaped endpoints. The probe destination is an unresolvable .invalid host — nothing is actually fetched off-site.