.NET MAUI and Xamarin Penetration Testing
A MAUI app ships your C# to the handset, and C# decompiles cleanly. Whatever logic you thought was hidden on the device, including the keys, is readable by anyone who pulls the package apart. CREST-certified testers, fixed price from £3,980, 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, CelloriIntermediate language decompiles back to near-original C#, which makes a MAUI or Xamarin package far more legible than a stripped native binary. Obfuscation raises the effort but does not change the conclusion: anything shipped to the device is available to whoever holds the device.
Why managed code on a handset is readable
That matters most for keys and logic. An API key compiled into an assembly is not protected, and a client-side authorisation check written in C# is a suggestion rather than a control. We look for both, then test whether the server enforces what the client merely asks.
The platform layer is the other half. MAUI and Xamarin sit on iOS and Android primitives, so keychain and keystore use, exported components, deep link handling and pinning implementation all behave like any other mobile app and are tested as such.
ISO 27001, SOC 2, PCI DSS and Cyber Essentials Plus audits accept manual penetration test evidence. Scan-only evidence is generally insufficient.
ASSEMBLIES, STORAGE + PINNING
What we actually pen test on a MAUI or Xamarin app
Manual pen testing across assembly decompilation, secure storage and keychain use, certificate pinning, platform channels and the API traffic behind the app.
Assembly decompilation and secrets
Package extracted and assemblies decompiled for hardcoded credentials, API keys, endpoints and business logic, obfuscation effectiveness, and whether debug or internal builds have shipped.
Secure storage and local data
SecureStorage, Preferences and file storage use, whether sensitive data is written in plaintext, keychain and keystore configuration, database encryption, and what survives logout or uninstall.
Certificate pinning and transport
Whether pinning is implemented and whether it can be bypassed on a rooted or jailbroken device, TLS configuration, ATS and network security configuration, and traffic interception resistance.
Platform channels and components
Dependency service and platform-specific code, exported Android activities and services, iOS URL scheme and universal link handling, and inter-process communication surface.
Tamper and runtime protection
Root and jailbreak detection where present and whether it can be defeated, debugger and hooking resistance, repackaging and resigning, and integrity checking.
Backend API and authorisation
The API behind the app tested directly with the app’s own credentials, whether server-side authorisation matches what the client enforces, session handling, and object reference flaws.
METHODOLOGY
.NET MAUI and Xamarin 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 MAUI 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 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
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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 .NET MAUI and Xamarin 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.
3 to 4 testing days
Single user role, basic CRUD application, marketing website with auth. Around 5 working days from kickoff to report.
Get a fixed quote4 to 6 testing days
Multi-role SaaS, business application with payment integration. Around 8 to 12 working days from kickoff to report.
Get a fixed quote6 to 8 testing days
Multi-tenant platform, complex authorisation matrix, integration-heavy applications. Around 15 to 20 working days from kickoff to report.
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
.NET MAUI and Xamarin 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 .NET MAUI and Xamarin 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
Do you test both iOS and Android builds?
Yes, and both are worth it. The shared C# is common but the platform layer differs, and we regularly find that secure storage or pinning is correctly implemented on one platform and not the other.
Do you need the source code?
No, and we usually work from the compiled package because that is what an attacker has. Source access speeds up triage and improves the write-up, so we take it when offered under NDA.
What about Xamarin apps we can no longer rebuild?
Common, and still testable. We work from the package as shipped. Where a finding cannot be fixed without a rebuild we say so plainly and suggest what can be mitigated server-side instead.
Is the backend included?
The API the app talks to is in scope, because most mobile findings are ultimately server-side authorisation failures. Full testing of a large backend is a separate engagement we can price alongside.
What do we receive?
A report mapped to the OWASP Mobile Top 10, ISO 27001 and SOC 2 where relevant, a developer write-up with reproduction steps, and unlimited free retesting.
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 MAUI or Xamarin app
Send us the builds for both platforms and tell us whether the backend API is in scope. Fixed-price quote from a named CREST assessor within one business day.
