You turn on your firewall in blocking mode, everything runs perfectly for days… and suddenly a customer messages you saying their card payment failed. You check the logs and there it is: your own firewall blocked Stripe or PayPal’s confirmation request, thinking it was suspicious traffic. The sale is already lost.
Why an aggressive firewall can break payments without you noticing
Payment gateways don’t just redirect the customer to their site and call it done — many send automatic requests back to your server (webhooks, asynchronous confirmations) to let you know a payment went through. If your firewall can’t tell those legitimate requests apart from any random bot, it can block them exactly the way it would block an attack — and you won’t know until a customer complains or you manually dig through the logs.
Why “allow anything that looks like a payment” isn’t enough
Anyone can pretend to be Stripe
Loosening your defenses generically — say, allowing any request that mentions “stripe” or “paypal” in the URL — is exactly the kind of hole a real attacker exploits, because that kind of text is trivial to fake. The fix isn’t relaxing the firewall, it’s making it recognize with certainty when the source really is the payment gateway.
Confirming the real source, not what the request claims to be
The difference is reliably verifying that a request truly comes from the payment gateway, instead of trusting what that request claims to be. That’s what lets legitimate traffic through without opening the door to anyone else — without having to loosen your defenses generically.
Why not every gateway is treated the same
Stripe, PayPal, Braintree and the rest don’t all work the same way under the hood, and each one has its own reliable way of confirming a request is genuinely theirs. Applying the same criteria to all of them equally, instead of giving solid protection, could fail at the worst possible moment without warning. That’s why SeenSecure adapts how it verifies each gateway instead of forcing one universal method onto all of them.
A layer that only acts when needed
This verification only makes sense when the firewall is genuinely in active blocking mode — in an observation-only mode, there’s nothing to “let through,” because nothing is being blocked yet. That’s why this layer is tied to the firewall’s actual protection mode, instead of being an independent setting someone could forget to coordinate with the rest.
Frequently asked questions
How do I know if my firewall is already blocking payment confirmations without my knowledge?
Check the firewall’s activity log for blocked requests related to your payment gateway — if there are any, that’s the clearest sign.
Does this mean anyone can pretend to be Stripe or PayPal and bypass my firewall?
No — traffic is only exempted from analysis when SeenSecure can reliably confirm it genuinely comes from the payment gateway, not just because of what the request claims to be.
Do I need to configure anything if I don’t sell anything with cards on my site?
No, this layer only matters if you use one of these payment gateways — if you don’t process online payments, it doesn’t affect you at all.