iOS vs Android penetration testing: key differences and what your app needs

By the QuantumSec team

iOS and Android share the same audit standard — OWASP MASVS/MASTG — but have different architectures, permission models and attack vectors. Auditing an app on both platforms isn't repeating the same work twice: each operating system exposes different attack surfaces that require specific methodology and tooling.

Different architectures, different threat model

iOS applies strict sandboxing and a closed ecosystem: each app runs in an isolated container with explicit permissions, and Apple controls distribution (App Store). Android is more open: the permission model is more granular but also more prone to misconfiguration, and installing outside Google Play (sideloading) is possible, which widens the exposure surface. This difference in philosophy determines what's more likely to fail on each platform.

iOS-specific attack vectors

Insecure storage in the Keychain or in unencrypted files accessible after jailbreak, jailbreak detection bypass, data transport without properly configured App Transport Security (ATS), poorly validated deep links, and extraction of secrets embedded in the binary (API keys, certificates) via reverse engineering with tools like Hopper or Ghidra.

Android-specific attack vectors

Unprotected exported components (Activities, Services, Broadcast Receivers accessible from other apps), root detection bypass, insecure storage in SharedPreferences or the SD card, poorly validated intents that allow injection or flow hijacking, and relatively straightforward APK decompilation with tools like JADX to expose business logic and embedded credentials.

One common methodology, a different technical approach

The OWASP MASVS (Mobile Application Security Verification Standard) and its MASTG testing guide define the same high-level security requirements — storage, cryptography, authentication, resilience against reverse engineering — for both platforms. But the technical execution of each test is specific: the tools, binary formats (IPA vs APK), native protection mechanisms and bypass techniques are not interchangeable between operating systems.

Do I need to audit both platforms if my app is on both?

Yes, in the vast majority of cases. Even if the backend and business logic are shared, each platform's client layer introduces its own vulnerabilities and depends on OS-specific security mechanisms. An app can be secure on iOS and vulnerable on Android (or vice versa) due to implementation decisions specific to each version. The reasonable exception is when the mobile client is a very thin wrapper over an API already audited independently, with no sensitive logic in the binary itself.

How to scope it if your budget is limited

If you can only audit one platform first, prioritize the one with the larger active user base or the one handling the most sensitive data flow (payments, health, financial data). Another reasonable option is auditing one platform in depth and doing a lighter review of the other focused on known implementation differences. What isn't advisable is assuming that auditing one platform covers the other.

FAQ

Does auditing iOS cost the same as Android?

Effort is usually similar when both apps have comparable complexity, though it can vary depending on each binary's exposed surface: an Android app with many exported components or an iOS app with complex obfuscation mechanisms may require more time on their respective platform.

If my app is hybrid (React Native, Flutter), do I still need to audit both platforms?

Yes. Even though the business code is shared in a cross-platform framework, each native build (IPA for iOS, APK/AAB for Android) packages that code differently and uses its own OS-native storage and communication mechanisms, which can introduce platform-specific vulnerabilities despite sharing the same codebase.

Does mobile pentesting include the backend/API the app consumes?

Mobile pentesting focuses on the client (the app installed on the device), but since the app always communicates with an API, it's common and advisable to also include a pentest of that API in the same scope to cover the full data flow.