Endpoint Security Question

Question

Random question that perhaps someone could shed some light on.My buddy and I are having an argument regarding one of our pages. The page is for unsubscribing from emails. Simple enough, the endpoint looks like this:Blah blah.com/emailpref?email=test@test.comThis takes them to a page saying. &ldquo;Thanks, John for visiting your email preferences page&rdquo;.From there they manage their email preferences.I told him that this is a super insecure design, and theoretically someone could brute force usernames and emails from this.Am I overreacting? What am I missing here?

ssklash · Accepted Answer

Pentester here. Absolutely something I would look at and abuse. You're disclosing information, allowing the harvesting of valid email addresses, and allowing access to an account. even if only in a limited capacity for email management, based on only the email. There's no reason to do it this way.See here: https://portswigger.net/web-security/access-control/idor