iOS vs Android Security Testing: What Actually Differs

Ask whether iOS or Android is “more secure” and you get a religious argument. Ask what differs when you test an app on each platform and you get a useful answer, because the platforms make different promises, expose different interfaces, and fail in different ways. The OWASP Mobile Application Security Verification Standard (MASVS) applies to both, but the test cases, the tooling, and the findings that come back are not the same.

This guide walks through the differences that matter in a mobile penetration test, so you know what to expect from each platform’s report and where your own app is most likely to be weak.

The platform security models in one paragraph each

iOS runs every app in a sandbox with a per-app data container, encrypts files with per-file keys tied to the device’s hardware and the user’s passcode (data protection classes), stores secrets in the Keychain, and distributes apps almost exclusively through the App Store, where binaries are encrypted and code must be signed. Apple controls the hardware, the OS, and the distribution channel, which narrows the attack surface and also narrows what a tester can see without a jailbroken device.

Android also sandboxes apps, using Linux user IDs and SELinux, encrypts storage at the file level on modern devices, stores secrets in the Keystore (hardware-backed where the device supports it), and distributes apps through Google Play and any other source the user allows. Hardware, OS versions, and vendor modifications vary widely, so the security a given app receives depends on the device it lands on, and sideloading means the app itself is easy to obtain and inspect.

The practical consequence: on Android, a tester starts with the app’s code in hand within minutes; on iOS, the tester’s first job is getting a decrypted binary and an instrumented device.

Reverse engineering: how much the tester sees

	iOS	Android
Getting the app	IPA is encrypted by the App Store; needs a jailbroken device or a decrypted build from you	APK downloads from Play or any mirror; nothing to decrypt
Decompiling	Native code (Swift, Objective-C) disassembled with Hopper or Ghidra; class and method names often recoverable	Java and Kotlin decompile to readable source with jadx; native libraries disassembled
Obfuscation	Less common; Swift symbols can be stripped	R8/ProGuard common but frequently misconfigured; strings and API keys usually recoverable
Typical finding	Secrets in plist files and hardcoded strings	Secrets in resources, BuildConfig, and hardcoded strings; debug leftovers

Because Android code is so readable, secrets embedded in the app are the most common Android finding we report: API keys, third-party credentials, and occasionally signing material. On iOS the same mistakes exist but take more work to reach, which changes how attackers prioritize, not whether the flaw is real.

Data storage: Keychain vs Keystore, and everything outside them

Both platforms give developers a secure place to put secrets and a dozen insecure places that are easier to use.

• iOS. The Keychain is the right place for tokens and credentials, and its accessibility class matters: an item marked AfterFirstUnlock is readable while the phone is locked and unlocked once, which is fine for a background sync token and wrong for a payment credential. Everything outside the Keychain depends on the file’s data protection class, and the default for many files is weaker than developers assume. Testing checks what survives an unencrypted backup, what the app writes to NSUserDefaults and plist files, what the pasteboard holds, and what the app snapshot shows when it is backgrounded.
• Android. The Keystore is the equivalent, hardware-backed on most devices, and the tester checks that keys are actually generated there with the right protections (user authentication required, no export). Outside it, the classic findings are plaintext credentials in SharedPreferences, unencrypted SQLite databases, sensitive data on external storage, and the allowBackup flag left enabled so the whole data directory can be pulled off the device.

The finding categories overlap; the specific locations and the flags that control them do not, which is why a platform-specific checklist matters.

Jailbreak and root detection: what it buys you

Both platforms let apps detect a compromised device, and both detections are bypassable. A tester removes them with instrumentation frameworks such as Frida and objection within the first hour, then tests what the app does afterward.

The useful question is not “does detection exist” but “what relied on it.” An app that stopped enforcing server-side checks because it trusted the client’s integrity has a real problem. An app that detects, warns, and continues to enforce everything on the server has a control that raises the attacker’s cost without depending on it. On Android, the Play Integrity API adds a server-verifiable attestation that is stronger than local checks; on iOS, App Attest plays a similar role. The report states whether these are used and whether the backend actually checks them.

Transport security and certificate pinning

• iOS. App Transport Security (ATS) enforces TLS by default, so the finding is usually an ATS exception that re-enables plaintext for a domain, or a pinning implementation that is present in the code but not wired to the actual network calls.
• Android. The Network Security Configuration file controls cleartext traffic, trusted certificate authorities, and pinning. The common findings are cleartextTrafficPermitted enabled for production domains, user-installed certificates trusted in release builds, and pinning that a single Frida script disables.

On both platforms, pinning is bypassed during the test so the API behind the app can be examined. Pinning slows an attacker down; it does not replace server-side authorization, and the report treats it that way.

Inter-process communication: the surface that is unique to mobile

This is where the platforms diverge most, and where many high-severity mobile findings live.

Android apps expose activities, services, broadcast receivers, and content providers. Any component that is exported, deliberately or by default in older SDK versions, can be invoked by another app on the device. Testing covers exported components that leak data or perform privileged actions, content providers that expose the database, implicit intents that can be intercepted, deep links that trigger sensitive flows without authentication, and WebViews that load attacker-controlled content with JavaScript bridges enabled.

iOS has a narrower IPC surface, which is one of the platform’s genuine advantages. The findings concentrate on custom URL schemes (any app can register the same scheme and hijack it), universal links that do not validate the incoming parameters, app extensions and shared containers that widen the data boundary, and WebViews with JavaScript bridges or file:// access.

Authentication and biometrics

Both platforms offer biometric APIs, and both are misused the same way: the app asks the OS “did the user pass biometrics?” and trusts a yes/no answer that an instrumented device can fake. The correct pattern binds the biometric result to a cryptographic operation: on iOS, a Keychain item protected by an access control flag requiring biometrics; on Android, a Keystore key that requires user authentication, used through BiometricPrompt with a CryptoObject. The test checks which pattern the app uses, and whether local authentication ever substitutes for server-side session validation.

Logging, debugging, and build hygiene

• iOS apps that log with NSLog or os_log write to the unified log, where sensitive values persist longer than developers expect.
• Android apps that log to logcat expose data to any app with log access on older versions, and debug builds shipped by mistake, debuggable set to true, or leftover test endpoints are found in a surprising share of production APKs.

Neither is glamorous; both appear in real reports and both are easy to fix.

What the typical findings look like

From engagements across both platforms, the findings that recur:

Platform	Frequent findings
iOS	Keychain items with weak accessibility classes; sensitive data in plist and cache files; ATS exceptions; URL scheme hijacking; biometric checks not bound to crypto; session tokens surviving logout
Android	Secrets in the APK; exported components and content providers; allowBackup and debuggable enabled; cleartext traffic; WebView JavaScript bridges; weak or bypassed root detection with server trust
Both	Backend API authorization failures (BOLA), which are the most severe category on either platform and are found by testing the API, not the app

That last row is the one that matters most. The app is the client; the data is on the server. A mobile test that stops at the binary has not tested the part that gets breached, which is why our mobile application penetration testing includes the backend API on every engagement.

Cross-platform frameworks

React Native, Flutter, and similar frameworks change the reverse-engineering picture (JavaScript bundles and Dart snapshots instead of native code) but not the platform findings. Storage still goes to the platform’s insecure locations if the framework’s defaults are used, IPC is still exposed through native shims, and pinning still has to be configured per platform. Cross-platform apps get tested on both platforms, not one.

What to give the tester

• Release or staging builds of both the IPA and the APK, ideally with the same code as production.
• Test accounts for each user role, and two accounts in each role where cross-user access matters.
• API documentation, or a Postman collection, for the backend.
• A note on which security controls you believe are in place (pinning, root detection, biometrics), so the report can confirm or contradict each one explicitly.

Our guide to the OWASP Mobile Top 10 covers the risk categories behind these findings, and the MASVS levels we test to are explained on the service page.

Frequently asked questions

Is iOS safer to ship on? The platform’s defaults are stricter and its IPC surface smaller, so an average iOS app inherits more protection. A carelessly built iOS app is still breachable, and the backend behind it is identical on both platforms.

Do we need to test both platforms if the code is shared? Yes. Storage, transport, IPC, and platform controls are configured separately, and the findings differ even when the business logic is the same.

Can you test without a jailbroken device or rooted phone? Partly. Static analysis and API testing work without one; full runtime testing of storage, pinning, and platform controls needs an instrumented device, which we provide.

How much does mobile application penetration testing cost? From $6,000 with both iOS and Android included, fixed before work begins, with a free retest. Starting prices for every service are on our pricing page.

Shipping on both platforms and want to know where each one is weak? Scope a mobile application test and we will cover iOS, Android, and the API behind them under one fixed price.