Web Security Series: Open Redirect Vulnerabilities

A real, trusted URL genuinely redirecting somewhere it shouldn't -- let's see the real fix. Code walkthrough (javascript): app.get('/goto', (req, res) =› { res.redirect(req.query.url); }); GET /goto?url=http://real-attacker-site.example const allowed = ['/dashboard', '/profile', '/settings']; if (!allowed.includes(req.query.url)) { return res.status(400).end('Real: invalid redirect target'); } // Real result: the untrusted external target // genuinely gets rejected now What it looks like: ❌ Real redirect target genuinely unchecked -- any real external URL accepted → ✅ Real allowlist genuinely rejects any target outside a known, real, internal set Try it yourself: Find one real redirect endpoint on your site and check if its target is genuinely validated. #websecurity #cybersecurity #webdev #javascript #coding #tutorial