Shopify App and Store Penetration Testing
Shopify secures the platform. Your apps, your theme code and your configuration are yours, and that is where the findings live. CREST-certified testers, fixed price from £2,180, scoped in 24 hours.
- Unlimited retesting
- No rescheduling or cancellation fees
- Fixed quote within 24 hours
“I would highly recommend EJN Labs to any organisation seeking reliable, detailed, and well-managed penetration testing services, particularly for government or enterprise-level projects.”
Imran SaghirProject Lead, SquareOne“There wasn’t another company we could find that could deliver what we needed in the timeframe we needed. The client loved it, and we got instant ROI from the engagement.”
Dan WilcocksonCo-Founder, CelloriShopify runs the checkout and the infrastructure, and they run it well. What we test is the part you own: the app you published or installed, the theme your agency wrote, the storefront tokens sitting in the page, and the configuration that decides who can do what.
The platform is not yours to test. Everything you built on it is.
Custom and public apps carry the most risk, because they hold an access token with whatever scopes the merchant approved. We look at how that token is stored, whether webhooks verify their signature, and whether the embedded admin surface trusts the session it is given.
Then the storefront. Theme code with custom JavaScript, metafields exposed by the Storefront API, discount and gift card logic, and third party scripts that sit alongside the checkout collecting more than anyone intended.
ISO 27001, SOC 2, PCI DSS and Cyber Essentials Plus audits accept manual penetration test evidence. Scan-only evidence is generally insufficient.
SHOPIFY SPECIFICS
What We Actually Test in a Shopify Build
Ten areas that apply because the store runs on Shopify, on top of the standard application checks. Every finding is verified, reproducible and mapped to OWASP, CWE and CVSS 3.1.
App OAuth and scopes
Scopes requested against scopes needed, the install flow, and how the offline access token is stored and rotated.
Webhook verification
HMAC verification on every webhook endpoint, replay handling and what an unverified webhook could trigger.
Embedded app session
Session token validation, iframe and origin handling, and whether the embedded admin trusts client-supplied shop parameters.
Admin API usage
Object level authorisation in your own app, tenant separation between merchants, and rate and error handling.
Storefront API and tokens
Public tokens in the page, what they can query, and metafields exposed that were meant to be internal.
Theme code
Custom JavaScript, Liquid output, injected snippets and anything rendering customer-supplied content.
Checkout and discounts
Discount and gift card logic, cart manipulation, quantity and price handling, and Plus scripts where present.
Customer accounts
Account creation, password reset, multipass or headless login flows and what customer data is reachable.
Third party scripts and pixels
Scripts loaded alongside the store, what they collect, and the consent that covers them.
Staff access and audit
Staff permissions, collaborator accounts, two factor coverage and what the activity log would show.
METHODOLOGY
What a Shopify app finding looks like
Written the way a finding appears in our reports. The example below is reconstructed from publicly documented research, with hosts, paths and identifiers redacted. We do not republish client findings, named or anonymised.
App webhook endpoint accepts unsigned requests
- Affected
- The order creation webhook on the app backend at [redacted], serving [redacted] merchant installs.
- What we found
- The endpoint did not verify the request signature, so any party could post an order payload. We created fulfilment records for orders that never existed and triggered customer email from the merchant domain.
- Why it matters
- Fabricated orders in the merchant admin, unwanted mail sent from the merchant domain, and a route into the app job queue that bypassed every check the storefront performs.
- Fix
- Verify the HMAC on every webhook with a constant time comparison before the body is parsed, reject requests with no signature, and treat webhook payloads as untrusted input rather than as trusted internal events.
Reconstructed from public research: the Shopify app development documentation, which requires HMAC verification of every webhook before the payload is processed.
Shopify Penetration Testing: From Scope to Attestation
CREST-aligned methodology built on OWASP Web Security Testing Guide, OWASP ASVS, NIST SP 800-115, and PTES. Each finding maps to all four standards plus your specific compliance regime.
Reconnaissance
Application mapping, technology fingerprinting, content discovery, parameter enumeration, authentication-flow analysis, role-matrix construction.
Vulnerability Assessment
Authenticated and unauthenticated automated scanning across every user role, plus targeted manual checks for known weakness patterns.
Manual Exploitation
Hands-on testing by a CREST-certified pentester. Business-logic exploitation, chained vulnerabilities, privilege escalation, impact validation.
Reporting + Retest
Executive summary, technical report with CVSS scores and reproduction steps, walkthrough call, free retest after remediation, attestation letter.
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 Shopify assessment 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 £2,180 for a small, single-scope engagement, agreed up front. Most engagements run £3,330 and up. No day-rate surprises.
Dan WilcocksonCo-Founder, 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
Quote request received
We will reply within one business day with your fixed-price quote from a named CREST assessor.
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or book a 20-min scoping call first
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COMPLIANCE READY
Reports Mapped to Every Framework
Findings are explicitly tagged to the relevant control reference. Your audit team submits the report directly 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 Shopify Penetration Testing Pricing
Pricing depends on app complexity, user-role count, business-logic depth, and integration surface. The day count flexes; the included deliverables stay the same across all engagements.
2 to 3 days
Single user role, basic CRUD application, marketing website with auth. Typically 5-day engagement.
Get a fixed quote3 to 4 days
Multi-role SaaS, business application with payment integration. Typically 8-12 day engagement.
Get a fixed quote4 to 6 days
Multi-tenant platform, complex authorisation matrix, integration-heavy applications. 15-20 day engagement.
Get a fixed quotePart of Technologies We Pen Test. These are examples of the stacks we publish pages for, not a complete list. If yours is not here we still test it. Related pages:
BY SECTOR
Shopify Penetration Testing for Your Sector
Sector-specialist scoping for UK businesses with sector-specific compliance regimes and threat models.
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 Shopify 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
Are you allowed to test Shopify?
We test your app, your theme and your configuration. Testing the platform itself follows Shopify policy and their bug bounty rules, which we respect.
We are a Shopify app developer, not a merchant.
Then this is the right page. Your app is a multi-tenant SaaS product, and tenant separation is the first thing we look at.
Do you need a development store?
Yes, ideally, with the app installed. That keeps live orders out of the test.
Does this help with an app store review?
It helps. The findings map to the protected customer data requirements developers have to meet.
What about a headless build?
Covered. The storefront API surface is in scope and so is whatever front end you built on it.
Is PCI in scope?
Shopify handles cardholder data. We test the boundary, which is where merchants most often create their own PCI problem.
What is included in the price?
Scoping, testing, the executive summary, the technical report, a walkthrough call and free retests until the finding is closed. One scope, one number, no follow-up invoices.
How fast can you start?
Scope to active testing in 24 hours once the scope is agreed, subject to tester availability in your window.
Are your testers CREST certified?
Yes. EJN Labs is a CREST member company and testing is delivered by CREST-qualified testers. The membership is verifiable on the CREST marketplace.
20+ CREST-accredited testing services in one place
Web, mobile, API, cloud, AI, infrastructure, red team. Pick the test that fits your environment.
Get your Shopify build tested properly
Tell us whether it is an app, a store or both. You will have a fixed scope and a number within 24 hours.
