Mobile Application Penetration Testing

We Break Into Your Mobile Apps on iOS and Android

Mobile apps handle sensitive data, authentication tokens, and payment flows – and they’re running on devices you don’t control. We reverse engineer your iOS and Android applications, test API communications, examine local data storage, and look for vulnerabilities that automated scanners miss entirely.

Our Testing Methodology

We follow the OWASP Mobile Application Security Verification Standard (MASVS) and Mobile Application Security Testing Guide (MASTG), combined with our own techniques developed across hundreds of mobile assessments. We test on real devices and emulators using tools including Frida, Objection, Jadx, Hopper Disassembler, and MobSF.

• Binary Analysis & Reverse Engineering: We decompile your APK or IPA and analyse the source code for hardcoded secrets (API keys, encryption keys, backend URLs), insecure cryptographic implementations, debug flags left enabled, and sensitive logic that should be server-side. On Android, we use Jadx and apktool; on iOS, we use Hopper and class-dump.

• Local Data Storage: We inspect how your app stores data on the device – SharedPreferences, SQLite databases, Keychain (iOS), KeyStore (Android), plist files, and application sandbox files. We check for sensitive data stored in plaintext, insecure encryption, and data that persists after logout.

• Network Communication: We intercept all API traffic using Burp Suite, bypassing certificate pinning with Frida scripts where implemented. We test for cleartext transmission, weak TLS configurations, certificate validation flaws, and API-level vulnerabilities (authentication, authorisation, injection) in the mobile backend.

• Authentication & Session Management: We test login flows, biometric authentication bypasses, token storage and rotation, session expiry handling, and OAuth/OIDC implementations. We look for tokens stored in insecure locations, missing revocation on logout, and client-side authentication checks that can be bypassed.

• Runtime Manipulation: Using Frida, we hook into running processes to bypass security controls, tamper with application logic, modify function return values, and test for root/jailbreak detection bypasses. This reveals whether your app’s client-side protections actually hold up against a motivated attacker.

• Inter-Process Communication (IPC): On Android, we test exported Activities, Content Providers, Broadcast Receivers, and deep links for unprotected access. On iOS, we test URL schemes, Universal Links, and App Extensions for input validation flaws and unauthorised functionality access.

Platform-Specific Testing

• Android: We test for insecure exported components, WebView vulnerabilities (JavaScript interface injection, file access via WebView), improper use of Android KeyStore, missing ProGuard/R8 obfuscation, debuggable builds, backup extraction via adb backup, and intent redirection attacks.

• iOS: We test for insecure data in Keychain with weak protection classes, pasteboard leakage, snapshot/screenshot caching of sensitive screens, App Transport Security (ATS) exceptions, Objective-C runtime manipulation, and Swift reflection abuse.

What We Typically Find

Representative findings from recent mobile assessments (anonymised):

• Hardcoded API Keys Leading to Full Backend Access: A fintech app embedded its admin API key in the Android APK. Using Jadx to decompile the binary, we extracted the key and used it to access administrative endpoints – including the ability to view and modify any user’s account balance.

• Certificate Pinning Bypass Exposing Token Theft: An e-commerce app implemented certificate pinning but used a bypassable method. Using Frida, we disabled the pinning check, intercepted the OAuth token exchange, and demonstrated how an attacker on a shared Wi-Fi network could hijack any user’s session.

• Biometric Bypass via Runtime Hooking: A banking app used biometric authentication for transaction approval. Using Frida to hook the authentication callback function, we modified the return value to always return “success” – bypassing fingerprint verification entirely and approving transactions without any biometric check.

Why Choose FORTBRIDGE?

• Senior-Only Engagements: Every mobile assessment is led by consultants with 10-20 years of offensive security experience, including dedicated mobile security expertise.

• Full-Stack Testing: We test the mobile app, its API backend, and the interaction between them – not just the client side in isolation.

• Developer-Focused Reporting: Every finding includes Frida scripts, screenshots, and step-by-step reproduction steps your mobile developers can use to verify and fix the issue.

• OWASP MASVS Aligned: Our methodology covers all verification requirements in the OWASP Mobile Application Security Verification Standard, providing a recognised benchmark for your mobile security posture.

Secure Your Mobile Applications

If you want to secure your mobile applications, connect with FORTBRIDGE for result-oriented mobile application penetration testing services. Protect your users’ privacy and take smart measures to secure your mobile applications.

Book a Discovery Call to discuss your requirements and get a scoping estimate.