E-commerce Website Security Testing Services

The classic e-commerce logic flaw. A price submitted from the browser and trusted by the server, a currency swapped for a cheaper one, a quantity set to a negative number that credits the order. We test whether the server independently verifies every figure that affects what you get paid, because if it trusts the client, an attacker will happily set their own prices.

Discount logic is where merchants lose margin quietly. We test whether a single-use code can be reused, whether codes can be stacked beyond your rules, whether a percentage discount can be pushed past a hundred percent, and whether an expired promotion still applies. These rarely make headlines, but they add up on a busy store.

One of the most damaging attacks on modern shops. A malicious script, injected through a compromised extension or a vulnerable checkout, copies card details as the customer types them and sends them to the attacker. The store keeps working perfectly, which is what makes it so dangerous. We review the scripts loaded on your payment pages and test the routes an attacker would use to plant one.

Customer accounts hold saved cards, addresses and order history, which makes them worth stealing. We test the login, the password reset and the session handling for the weaknesses that let an attacker take over an account, then check what that account can see and do, including whether it can view or alter other customers’ orders.

The money leaves through the back office as well as the checkout. We test whether a customer can trigger a refund or store credit they are not owed, refund an order more than once, or turn a returned item into free value by exploiting the sequence of steps in your returns flow. On stores with generous return policies these gaps are quietly expensive.

We inventory the platform, its theme, and every extension or plugin it runs, because in retail the third-party code is often the weakest link. An abandoned payment plugin or an outdated page builder is a common entry point, and content discovery frequently turns up an admin panel or an old checkout version still live.

We work through browse, cart, checkout and payment as an attacker would, manipulating each step and watching how the server responds. This is where price, coupon and quantity logic gets stressed, and where the payment integration’s trust in the browser and the gateway’s webhooks is tested.

You get an executive summary for the business and a technical report for whoever maintains the store, with every finding scored by CVSS, its impact stated in terms of lost revenue or exposed data, exact reproduction steps and a specific fix. After you remediate, the retest is included so you can prove the store is secure before a busy trading period.

Requirement 11.4 calls for regular penetration testing of the application, and requirements 6.4.3 and 11.6.1 were added to address exactly the client-side skimming threat that has cost so many merchants: they require you to manage and monitor the scripts loaded on your payment pages and to detect unauthorised changes. Our testing and reporting are built to support all three, and an attestation letter is available for your acquirer or QSA.

Beyond cards, an online store holds personal data that GDPR covers, and testing supports the technical measures it expects. For ISO 27001 the results feed control A.8.29 and your risk records; for SOC 2 they serve as independent evidence under the security criteria your auditor reviews. A single dated report often answers several of these obligations at once, which is worth knowing when you are juggling more than one framework.

Fraudsters use a checkout or a saved-card feature to validate stolen card numbers in bulk, running thousands of small authorisations to see which cards are live. Beyond the fraud itself, this triggers chargebacks and can put your merchant account at risk. We test whether your payment flow has the rate limiting and controls to make this expensive rather than trivial.

Scalping bots reserve or buy limited stock faster than any human, and account-checking bots use your login to test stolen credential lists against your customer base. We test whether an attacker can enumerate valid accounts, reserve inventory without completing a purchase, or race two requests to grab a limited item twice.