Braintree Integration Penetration Testing
Braintree turns a card or wallet into a payment method nonce, but your server decides what that nonce is worth. We test the transaction, webhook and vault logic you built around it. CREST-certified testers, fixed price from £3,120 for a 2-day single-integration scope, quoted within 24 hours.
- Unlimited retesting
- Unlimited pre-retesting
- No hidden fees
“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.”
“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.”
A payment method nonce is a single-use reference to whatever the client tokenised, a card, PayPal, or a wallet. It proves something was submitted to Braintree, not that your server checked what it was for or how much it should cost.
A nonce reaching your server proves nothing about the amount or the account it belongs to
Braintree’s client SDKs turn whatever a customer enters, a card, PayPal, a wallet, into a payment method nonce, and it is your server’s job to decide what that nonce is used for. The client token guide confirms the token your server issues is a signed JWT valid for up to 24 hours, and that it is invalidated if the customer ID tied to it creates an excessive number of payment methods. Neither control does anything for an integration that treats a nonce arriving at the server as proof the customer paid, rather than as a claim still waiting to be checked.
The transaction itself is only ever created server-side, with a call such as transaction.sale, and Braintree’s transactions guide is explicit that the amount, currency and settlement options in that call are whatever your code passes it. Braintree does not recompute a total from a cart on its side, and a merchant account ID in the same call decides which currency and which account the money settles to. An integration that reads its amount, or its merchant account, from something the browser sent has handed both decisions to the customer.
The rest of the risk sits in how the pieces around the transaction are wired. A webhook notification arrives as bt_signature and bt_payload parameters that only mean something once your handler calls the parse method and it raises on an invalid signature, so a handler that skips that step acts on whatever is posted to it. A vaulted payment method needs to stay bound to the customer it was created for, not whichever customer ID a request happens to supply. And the merchant_id, public_key and private_key that authenticate your server, along with any Braintree Marketplace sub-merchant setup, need to stay server-side and stay separated between sandbox and production.
SCOPE
What we pen test on a Braintree integration
Client token generation and scope
Whether your server generates the client token per session and scopes it to the authenticated customer ID rather than reusing one long-lived token across users, and what a leaked token can actually do given it authorises tokenisation, retrieval and vaulting for up to 24 hours.
Payment method nonce handling
Whether a nonce returned to the client is genuinely single-use, whether the client-side code that requests it can be manipulated into tokenising a different payment method than the one shown to the customer, and what happens if the same nonce reaches your server twice.
Server-side transaction creation and amount integrity
Whether transaction.sale is called with an amount and currency computed from your own order records, not one read back from the browser, and whether the response is checked for a genuine authorised status before your application treats the order as paid.
Settlement, void and refund authorisation
Who can trigger submit_for_settlement, a void or a refund against a transaction, whether the amount and currency are checked against the original authorisation, and whether an authenticated customer can act on a transaction ID that belongs to somebody else.
Webhook signature verification
Whether your listener passes the bt_signature and bt_payload parameters to the parse method on every request and handles the invalid signature exception it raises, rather than reading the kind and payload straight out of an unverified POST body.
Webhook idempotency and event handling
Whether a repeated or out-of-order webhook, since Braintree does not guarantee sequential delivery, can trigger a second fulfilment or overwrite a more recent transaction state in your own systems.
Vaulted payment methods and customer binding
Whether a payment method token created for one customer can be read, updated with make_default, or deleted by a request authenticated as a different customer, and whether card verification is actually enabled before a method is stored.
Customer creation and card verification
Whether creating a customer with an attached payment method nonce is restricted to your own authenticated session, whether verify_card is enforced so a stored card is actually checked before it sits in the vault, and whether validation errors leak details about existing customers.
Merchant account and multi-merchant configuration
Whether the merchant account ID that decides which currency and which account a transaction settles to is fixed server-side or can be influenced by request data, and, where Braintree Marketplace is in use, whether sub-merchant onboarding, service fees and escrow disbursement are authorised the way you intended.
API credential handling and environment separation
Whether the merchant_id, public_key and private_key used to initialise the server SDK ever reach client-side code or a public repository, and whether sandbox credentials, which Braintree issues as an entirely separate login from production, can reach a production endpoint or vice versa.
OUR PROCESS
Braintree Integration Penetration Testing: From Scope to Attestation
Scope the integration
We list every Braintree touchpoint in your application: client token issuance, nonce handling, transaction creation, webhooks, vaulted payment methods and merchant accounts, and confirm which credentials belong to sandbox and which belong to production.
Test against the Braintree Sandbox
Transaction, webhook, vault and refund logic is tested against your sandbox merchant ID and API keys wherever the check allows; anything that genuinely needs live Braintree is agreed with you first and run read-only.
Exploit the business logic
CREST-certified testers chain findings across the transaction, webhook and vault flow, covering amount tampering, forged or replayed webhooks, nonce misuse and customer-binding gaps rather than relying on scanner output alone.
Report and retest
Executive summary, technical report with CVSS scores and reproduction steps, a walkthrough call, free retest after remediation, and an 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 Braintree 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
Quote request received
We will reply within one business day with your fixed-price quote from a named CREST assessor.
Your data stays with us. No newsletter signup.
or book a 20-min scoping call first
We reply within one business day. Your data stays with us. No newsletter signup.
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 Braintree 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 5 testing days
Multi-role SaaS, business application with payment integration. Around 8 to 12 working days from kickoff to report.
Get a fixed quote5 to 7 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 Braintree 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 Braintree 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?
A sandbox merchant ID, public key and private key for the integration under test, and a sandbox account to generate test nonces. We do not need your live Braintree or PayPal Control Panel login, and only need scoped, read-only production access where a specific check requires it.
Does this touch live transactions or real money?
No, wherever the check allows. Braintree’s sandbox is an entirely separate environment from production, with its own merchant ID and API keys, and lets us run sales, refunds, webhooks and vault operations with mock data. Anything that must run against live Braintree is agreed with you in advance and scoped tightly.
How long does a Braintree integration test take?
A single integration is a 2-day scope. Multiple payment method types such as cards, PayPal and wallets in the same checkout, Braintree Marketplace sub-merchant flows, or a second payment provider alongside Braintree add testing days, which we agree before the engagement starts.
We use Drop-in UI or Hosted Fields rather than a custom form. Is there still anything to test?
Yes. Drop-in and Hosted Fields reduce how much raw card data reaches your client, but the client token your server issues, the nonce your server exchanges, the transaction and webhook logic, and how payment methods are vaulted against a customer are still your code.
What is out of scope?
Braintree’s own gateway, processing infrastructure and fraud engine. We test the integration your team built: client token issuance, transaction and settlement logic, webhook handling, vault and customer binding, and merchant account configuration, never Braintree’s or PayPal’s platform itself.
Does Braintree have a policy on this kind of testing?
Braintree’s own testing reference confirms the sandbox is an entirely separate environment from production, with its own login, merchant ID and API keys, so nothing created there reaches live processing. We test against your sandbox credentials for that reason, and confirm your account’s current terms for anything that must touch production during scoping.
Our checkout also accepts PayPal through Braintree. Is that covered?
Yes, if your integration uses Braintree’s PayPal payment method type it is tested as part of this scope. If you also run a direct PayPal integration outside Braintree, see our PayPal integration penetration testing page, the checks overlap but the API surface is different.
Do you test Braintree Marketplace or sub-merchant setups?
If your integration uses Braintree Marketplace, yes. We scope in sub-merchant onboarding, onboarding confirmation, service fee handling and escrow disbursement alongside the standard transaction and webhook checks; tell us at quoting stage if Marketplace is part of your setup.
20+ CREST-accredited testing services in one place
Web, mobile, API, cloud, AI, infrastructure, red team. Pick the test that fits your environment.
Get a fixed price for your Braintree integration
Braintree turns a card or wallet into a payment method nonce, but your server decides what that nonce is worth. We test the transaction, webhook and vault logic you built around it. CREST-certified testers, fixed price from £3,120 for a 2-day single-integration scope, quoted within 24 hours.
