Mobile App Penetration Testing: Android & iOS Guide

• Offensium Vault
• October 24, 2026
• No Comments

Mobile apps now handle logins, payments, health records and personal data for millions of users, often with less scrutiny than the websites they replaced. Mobile app penetration testing checks how an attacker could abuse your Android or iOS app, the data it stores on the device and the APIs it talks to, before real attackers find the same weaknesses.

This guide explains what mobile app penetration testing covers, how Android and iOS testing differ, which standards a good test follows and how to prepare your team for one.

What Is Mobile App Penetration Testing?

Mobile app penetration testing is a security assessment in which testers analyse your app the way an attacker would: unpacking the installed app, inspecting how it stores and transmits data, intercepting traffic to its backend and trying to bypass its security controls. The goal is to find exploitable weaknesses, prove their impact and give your developers clear guidance to fix them.

A complete test looks at three layers:

• The app on the device: local storage, hard-coded secrets, permissions, platform interactions and resistance to tampering.
• The network layer: how securely the app communicates with servers, including TLS configuration and certificate validation.
• The backend APIs: authentication, authorisation and business logic on the servers the app relies on.

Why Mobile Apps Need Dedicated Security Testing

Once your app is published, anyone can download it and examine it at leisure. Attackers can decompile the code, read embedded keys and URLs, modify the app’s behaviour on a rooted or jailbroken device and call your APIs directly without using the app at all. Security controls that only exist in the app’s interface can therefore be bypassed easily, which is why both the app and its backend must be tested together.

The OWASP Mobile Top 10 (2024)

The OWASP Mobile Top 10 highlights the most common and serious mobile risks. The 2024 edition lists:

1. Improper Credential Usage
2. Inadequate Supply Chain Security
3. Insecure Authentication/Authorization
4. Insufficient Input/Output Validation
5. Insecure Communication
6. Inadequate Privacy Controls
7. Insufficient Binary Protections
8. Security Misconfiguration
9. Insecure Data Storage
10. Insufficient Cryptography

For detailed test cases, testers typically follow the OWASP Mobile Application Security project, which includes the MASVS verification standard and the MASTG testing guide. MASVS groups requirements into areas such as storage, cryptography, authentication, network, platform interaction, code quality, resilience and privacy.

Mobile App Penetration Testing Checklist

Data Storage and Privacy

• Check whether passwords, tokens or personal data are stored in plain text in local files, databases, shared preferences or the iOS keychain.
• Look for sensitive data in logs, screenshots, the clipboard, backups and caches.
• Confirm the app only collects and shares the data it genuinely needs.

Authentication and Session Handling

• Test login, biometric unlock, OTP and password reset flows for bypasses.
• Verify that session tokens expire and are invalidated on logout.
• Confirm authorisation checks happen on the server, not only in the app.

Network Communication

• Intercept traffic to confirm all communication uses properly validated TLS.
• Check whether certificate pinning is used where appropriate and how easily it can be bypassed.
• Ensure no sensitive data is sent in URLs or to third-party analytics unintentionally.

Code, Secrets and Binary Protection

• Decompile the app to look for hard-coded API keys, credentials and internal endpoints.
• Assess obfuscation, root and jailbreak detection and anti-tampering controls, based on your risk level.
• Identify outdated or vulnerable third-party SDKs and libraries.

Platform Interaction

• Test deep links, intents, URL schemes and exported components for abuse.
• Review WebViews for unsafe JavaScript bridges and content loading.
• Check requested permissions against what the app actually needs.

Backend APIs

• Test for broken object-level authorisation, such as one user accessing another user’s orders or profile.
• Check rate limiting, input validation and business logic on every endpoint the app uses.

Because the backend is often where the most serious issues are found, mobile testing pairs naturally with an API security assessment.

Android vs iOS Penetration Testing

Most businesses ship on both platforms from a shared backend, so testing both apps together gives the most complete picture and avoids duplicate effort on the APIs.

How to Prepare for a Mobile App Penetration Test

1. Share the latest builds (APK/AAB and IPA, or TestFlight access) and confirm the version in scope.
2. Provide test accounts for each user role, with test payment or OTP options where needed.
3. List the backend APIs and environments that are in scope.
4. Tell testers about any security controls, such as certificate pinning or root detection, so they can plan accordingly.
5. Agree timelines, contacts and how findings will be shared securely.

What You Should Receive

A good report includes an executive summary, each finding with severity, evidence and steps to reproduce, and practical remediation advice for both mobile and backend developers. Insist on a retest after fixes, so you know the issues are genuinely closed. For a broader view of how this fits into your overall testing programme, see our web application penetration testing checklist.

Frequently Asked Questions

How is mobile app penetration testing different from web application testing?

Mobile testing covers everything a web test does for the backend APIs, plus risks that only exist on the device: how the app stores data locally, whether secrets are hard-coded in the binary, how it uses platform features such as deep links and permissions, and how easily it can be reverse engineered or tampered with.

Do you need the source code to test a mobile app?

No. Testers can work from the compiled app (APK, AAB or IPA) and test accounts. Providing source code or a debug build allows a deeper, faster review, and is useful for apps that handle payments or sensitive personal data.

How often should a mobile app be tested?

Test before the first public release, after major feature changes such as new login, payment or data-sharing flows, and at least once a year. Because app and backend releases are frequent, many teams also add automated security checks to their CI/CD pipeline between manual tests.

Conclusion

Mobile app penetration testing protects the part of your business that sits in your customers’ pockets. By testing the app on the device, its network traffic and the APIs behind it against recognised standards such as the OWASP Mobile Top 10 and MASVS, you can release with confidence and fix issues before they become incidents.

Planning a release or a security review for your Android or iOS app? Learn more about our mobile app penetration testing service or contact the Offensium Vault team for a scoping call. You can also browse all our cybersecurity services.