BigCommerce Store and Integration Penetration Testing
A BigCommerce store carries two layers of risk that rarely get reviewed together: the store itself, its API accounts, installed apps and checkout customisations, and the code a developer has written to extend it into an app or a headless front end. Whether you are the merchant reviewing what your own store now exposes, or the developer shipping that app or integration, we test the configuration and custom code you control. We never treat BigCommerce’s own platform as the target. CREST-certified testers, fixed price from £2,180 for a 2-day single-platform scope, quoted within 24 hours.
- Unlimited retesting
- Unlimited pre-retesting
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BigCommerce’s OAuth consent screen makes a merchant accept every scope an app requests in a single step. There is no partial approval, so an app asking for more than it needs gets all of it.
Why BigCommerce findings sit in your apps and integrations, not the platform
BigCommerce issues three kinds of OAuth-based API account for a store: a store-level account with a static access token, an app-level account that gets a fresh access token every time a store installs the integration, and an account-level account tied to whoever manages several stores from one login. Each carries its own set of OAuth scopes, most available as a full or a read-only variant, and a merchant installing an app from the BigCommerce marketplace has to accept every scope it asks for in one step, with no option to grant less. We test which accounts exist, what scopes each one actually holds, and whether that still matches what the integration does.
A custom checkout built with the Checkout SDK handles address selection, coupons and gift certificates, payment initiation and order completion in the browser, so that is exactly where we test for logic trusting a value the browser sent rather than one the server recalculated. Checkout Content scripts sit on the same page under a separate scope and get the same scrutiny. BigCommerce’s webhook payloads are deliberately thin, an order status change carries only the order ID, and webhook subscriptions sit under a default scope every API account already has, so even a narrowly scoped account can register one pointing anywhere.
Where the storefront is headless, a GraphQL Storefront API token carries its own risk depending on type: a browser-facing storefront token scoped to specific CORS origins, a private token for server-to-server calls, or a customer impersonation token that lets whoever holds it query the API as a named customer. Order and channel-listing data reaching an ERP, fulfilment tool or marketplace channel follows the same pattern, a webhook event followed by an authenticated call back into the API for the detail, so the account making that call is as much in scope as the system receiving it. None of this is a flaw in BigCommerce itself. It is what your team, or the developer you hired, built on top of it, and that is what we test.
SCOPE
What we pen test on a BigCommerce store
Storefront Customer Accounts and Login
Customer registration, login and password reset on the storefront, plus the Customer Login API, which signs a customer in using a JWT your application creates rather than a password the customer types. We test how that token is generated, signed and scoped, and whether it can be reused to sign in as a different customer.
Checkout SDK and Custom Checkout Logic
A Checkout SDK build runs address selection, coupon and gift certificate application, payment initiation and order completion in the browser. We test whether any of those steps trust a value the browser sent rather than one the server recalculated, particularly around price and discount handling.
Checkout Content and Injected Scripts
Scripts added to the checkout page, through the scope that manages store scripts, run alongside card entry and customer data. We test what each script can read or change on that page and whether its source is still what it was when it was approved.
Store-Level and Account-Level API Accounts
Every API account carries a client ID, a client secret and an access token, and a store-level account’s token is static rather than rotating. We check which accounts exist, who or what holds each one, and whether their scopes still match the integration they were created for.
Installed Apps and OAuth Scope Consent
Installing an app from the BigCommerce marketplace means accepting every scope it asks for in one step, with no way to grant a narrower set. We test what each installed app can actually reach against what its function requires, and flag any app holding scope it has no use for.
Webhook Endpoints and Signature Verification
Webhook subscriptions sit under the default scope every API account already has, so even a narrowly scoped account can register a webhook pointing at any destination. Payloads carry little more than an event type and an ID, so we test whether the receiving endpoint verifies the webhook signature before it calls back into the API for the rest.
Headless Storefront and GraphQL API Tokens
A headless front end authenticates to the GraphQL Storefront API with a storefront token scoped to specific CORS origins, a private token for server-to-server calls, or a customer impersonation token that queries the API as a named customer. We test which type is in use, how long it lives, and what it can reach.
Order Data, Channels and ERP Integrations
Order and channel-listing data reaching an ERP, fulfilment tool or marketplace channel follows BigCommerce’s own pattern: a webhook event triggers an authenticated call back to the Orders API for the detail. We test the account making that call as closely as the system receiving it.
Storefront Content, Pages and Widgets
Store pages, blog posts, redirects and widgets are all reachable through a single content scope, and we test whether that scope, and whoever holds it, is limited to what your content team actually edits.
Payment Provider Configuration
Payment access tokens are created and used to process payments through a scope kept separate from general checkout access, and we test how that token is stored, which accounts can create one, and whether your configured payment provider is set up the way your team intended.
OUR PROCESS
BigCommerce Store and Integration Penetration Testing: From Scope to Attestation
Scope and Account Mapping
We agree the environments, accounts and integrations in scope, and map every API account, OAuth scope, installed app, webhook destination and checkout customisation before testing begins.
Automated and Authenticated Scanning
Authenticated scanning runs against the storefront, the admin control panel and each API account’s actual scope, alongside targeted checks for known BigCommerce configuration weaknesses.
Manual Exploitation
A CREST-certified tester manually tests token scope boundaries, checkout and webhook logic, and app access, chaining findings where they compound across the store and its integrations.
Reporting and Retest
You get a technical report with CVSS scores and reproduction steps, a walkthrough call, a free retest once fixes are deployed, and an attestation letter for auditors.
CREDENTIALS
Verified Accreditations Auditors Accept
Every credential below is independently verifiable. UK procurement teams, FCA supervisors, ISO 27001 / SOC 2 auditors, and cyber insurance underwriters all recognise these standards.
GET YOUR QUOTE
Get a CREST BigCommerce pen test quote in 24 hours
A fixed-price quote back in one business day, from a named CREST assessor. No sales pipeline, no chasing.
- CREST and IASME accredited. Testing your auditors and clients already recognise.
- Fast-track testing within 24 hours where required. Free retest of every fix included.
- Live findings via your client portal, not a four-week PDF.
- Fixed price from £3,500 for a single-role, single-app scope, agreed up front. Most engagements run £5,000 and up. No day-rate surprises.
Dan WilcocksonFounder, CelloriUnder NDA Further named references available on a scoping call.
- We reply within one business day with a fixed-price quote from a named CREST assessor.
- You approve the scope and we book a start date, usually within 24 hours.
- Live findings land in your client portal as we test, with a free retest of every fix.
Get your fixed pen test quote in 24 hours
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COMPLIANCE READY
Reports Mapped to Every Framework
Findings are written so your team can reference the report against each framework without translation work.
ISO 27001:2022
Annex A.8.8 management of technical vulnerabilities plus A.5.15-5.18 and A.8.2-8.5 access control validation.
SOC 2 Type I & II
CC6 logical access, CC7 system operations, CC8 change management evidence.
PCI DSS
Requirement 11.4 application penetration testing across cardholder data environments, including ecommerce penetration testing for online retail platforms.
FCA SYSC
SYSC 4.1.1R, 6.1.1R, 13 mapped to each finding for FCA-regulated firms.
UK GDPR
Article 32 effectiveness testing, customer-data security controls, ICO-acceptable evidence.
Cyber Essentials Plus
Direct certification through our IASME body status, single-vendor delivery.
PRICING
Transparent BigCommerce Store and Integration Penetration Testing Pricing
Pricing depends on the number of roles, integrations and environments in scope. See our pricing page for how we quote.
2 to 3 testing days
Single user role, basic CRUD application, marketing website with auth. Around 5 working days from kickoff to report.
Get a fixed quote3 to 4 testing days
Multi-role SaaS, business application with payment integration. Around 8 to 12 working days from kickoff to report.
Get a fixed quote4 to 6 testing days
Multi-tenant platform, complex authorisation matrix, integration-heavy applications. Around 15 to 20 working days from kickoff to report.
Get a fixed quoteSECTORS
Sectors We Test BigCommerce For
Sector-specific scoping for regulated UK organisations.
Fintech & FCA-Regulated
FCA SYSC, Open Banking FAPI 1.0, PSD2 SCA, payment-flow scrutiny, KYC/AML testing.
Fintech sector pageSaaS Companies
SOC 2 Type I & II evidence, multi-tenant boundaries, role escalation, customer-tenant isolation.
SaaS sector pageLaw Firms
SRA Cyber Standard, privileged data, conveyancing fraud defence, partner-tier procurement.
Law firm sector pageHealthcare
NHS DTAC, DSP Toolkit v6, UK GDPR Article 32, EHR systems, telehealth platforms.
Healthcare sector pageInsurance
FCA / PRA Operational Resilience, cyber underwriting, claims data, broker portals.
Insurance sector pagePublic Sector
CCS / G-Cloud framework, NCSC-aligned, citizen-facing services, PSN-compliance scrutiny.
Public sector pageWHY EJN LABS
What You Get From BigCommerce Store and Integration Penetration Testing
Six concrete differentiators competitors don’t all match.
CREST-Certified Testers, Verifiable
Every test by a CREST-certified pen tester (CRT, CCT APP, CCT INF where applicable). Verify our company status at crest-approved.org.
24-Hour Startup, Where Required
From signed scope to active testing in a single business day for incident response, audit deadlines, or regulator-driven timelines.
Live Findings, Not 4-Week PDFs
Critical issues reported during testing through your client portal. Your team remediates while testing continues.
Audit-Ready Reports
Executive summary plus full technical report with CVSS scores and explicit framework mappings (ISO 27001, SOC 2, PCI DSS, FCA SYSC).
Free Retests, Standard
Verify remediation of every finding before close-out. Letter of attestation for audit submission included. Most competitors charge £1,500-£3,000 per retest.
UK-Based CREST Testers
Every engagement performed by vetted, UK-based CREST-certified testers, matched to your needs, security clearance, and compliance scope.
FAQ
Frequently Asked
What access do you need to test our BigCommerce store?
A staff login with a role you control, so we see the store the way your team manages it day to day, plus at least one customer account on the storefront. Where an app, a headless front end or an ERP integration is in scope, its own API account or Storefront API token comes too, scoped to what that integration is meant to do rather than a full-access account created just for us.
Does this touch our live data?
No. We test against a staging store or a cloned copy of your catalogue and customer data wherever one exists. Where only production is available, any check that could place a real order or move real payment data is agreed and scoped in advance, and read-only checks are logged as they happen.
How long does a BigCommerce penetration test take?
A single-platform BigCommerce engagement is scoped at 2 testing days as a starting point, rising with the number of installed apps, storefront channels and integrations in play. Reporting and a walkthrough call follow testing, with a free retest once fixes are in.
BigCommerce is a hosted platform. What does that leave in scope?
The underlying storefront and admin infrastructure is managed by BigCommerce, so it is not something your configuration changes and it stays out of scope. Testing concentrates on your store’s API accounts and their scopes, installed apps, checkout customisations, webhook endpoints, and any headless front end or ERP integration you have built or commissioned.
What is out of scope?
BigCommerce’s own platform infrastructure and other merchants’ stores. Third-party apps you have installed are tested for what they can reach given the scopes you granted them, not audited as a vendor’s product in their own right, and any wider cloud or network review sits outside a single-platform BigCommerce engagement unless you scope it alongside this one.
Does BigCommerce have a policy on testing your own store’s security?
BigCommerce’s Acceptable Use Policy lists penetrating or attempting to penetrate security measures, port scans and stealth scans as prohibited Hacking when done without authorisation, and does not publish a separate carve-out for a merchant testing their own store. We confirm the current terms with you during scoping, and our testing targets the store configuration, custom code and integrations you control rather than BigCommerce’s platform infrastructure.
Do you test the apps we have installed from the BigCommerce App Marketplace?
We test what each installed app can reach given the OAuth scopes it holds, since a merchant has to approve every scope an app requests in one step at install with no option to grant less. We do not audit that as a vulnerability review of the app vendor’s own code, which stays theirs to secure.
We are a developer building an app or a headless storefront, not the merchant. Can you test that instead?
Yes. The engagement scopes the same way, against your app’s OAuth flow and access tokens, its webhook endpoint, and your Storefront API or GraphQL integration, using a development or sandbox store rather than a live merchant’s data.
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Get a fixed price for your BigCommerce store or integration
A BigCommerce store carries two layers of risk that rarely get reviewed together: the store itself, its API accounts, installed apps and checkout customisations, and the code a developer has written to extend it into an app or a headless front end. Whether you are the merchant reviewing what your own store now exposes, or the developer shipping that app or integration, we test the configuration and custom code you control. We never treat BigCommerce’s own platform as the target. CREST-certified testers, fixed price from £2,180 for a 2-day single-platform scope, quoted within 24 hours.
