Mobile applications place business services directly onto devices that organisations do not fully control. Customers and employees may use them on personal phones, outdated operating systems, compromised devices, or networks that the business cannot monitor.

Unlike a conventional website, a mobile app also leaves installable code on the device. Attackers can download that code, inspect it, modify it, observe how it communicates, and study how it handles sensitive information.

Mobile application vulnerability assessment and penetration testing, or mobile application VAPT, examines how an Android or iOS app behaves under these conditions. It helps identify weaknesses in local storage, authentication, platform interaction, network communication, privacy controls, and resistance to tampering.

The OWASP Mobile Application Security Verification Standard groups mobile security controls across storage, cryptography, authentication, network communication, platform interaction, code quality, resilience, and privacy. These areas provide a useful basis for assessing both Android and iOS applications.

Why Mobile Apps Need Their Own Security Assessment

A mobile app is more than another interface for a website. It is a software package installed on a device, with access to operating system features, local files, sensors, notifications, links, and external services.

The mobile device must be treated as a potentially hostile environment. An attacker may control the device, intercept application traffic, alter runtime behaviour, or examine the app package for secrets and hidden functions.

This creates risks that ordinary web application testing may not fully cover. A browser-based assessment can examine server-side functions, but it may not reveal data written to mobile storage, insecure inter-app communication, exposed application components, or protections that can be bypassed on a modified device.

Mobile apps should therefore be included when identifying business-critical digital assets that require testing, even when the app appears to provide the same services as an existing website.

Mobile Risks That Server-Side Testing Can Miss

Sensitive Data Stored on the Device

Mobile apps may store login tokens, customer details, downloaded documents, cached responses, encryption keys, payment information, or internal business data.

Sensitive information can appear in databases, preference files, temporary files, screenshots, logs, backups, clipboard contents, or notifications. A user may never notice that the app has left this information behind.

Android and iOS provide secure storage mechanisms, but developers must implement them correctly. Mobile VAPT checks whether the app stores only the data it needs and whether sensitive information remains protected if someone gains access to the device or application files.

Reverse Engineering and Application Tampering

Android packages and iOS application binaries can reveal information about how an app works.

An attacker may search the application for embedded credentials, API keys, internal URLs, test functions, encryption routines, business rules, or security checks. They may also modify the app to remove restrictions, alter transaction behaviour, bypass licence controls, or disable security warnings.

Code obfuscation and integrity checks can make this activity more difficult, but they do not replace secure server-side enforcement. Important decisions should not depend entirely on logic contained within the mobile app.

Testing examines how easily the application can be analysed or altered and whether tampering allows an attacker to gain meaningful access or manipulate a protected process.

Deep Links and Inter-App Communication

Mobile operating systems allow apps to open specific content through deep links, URL schemes, intents, universal links, and other communication mechanisms.

These features improve usability, but unsafe handling can allow attackers to pass malicious data into the app, open restricted screens, trigger unintended actions, or intercept links intended for another application.

Testing should confirm that links do not bypass authentication, trust unvalidated parameters, expose sensitive records, or allow another installed app to misuse exported functions.

WebViews and Embedded Browser Content

Many mobile applications display web content inside an embedded browser component rather than sending the user to a separate browser.

This can introduce risk when the app loads untrusted URLs, enables unnecessary JavaScript functionality, exposes native functions to web content, or fails to validate redirects.

Testing an embedded WebView may overlap with security testing for web-based application components, but the assessment must also examine the connection between the web content and the native mobile app.

Excessive Permissions and Privacy Exposure

Mobile apps can request access to cameras, microphones, contacts, storage, location data, Bluetooth devices, photos, and other sensitive resources.

Some permissions may be necessary, but unnecessary access increases the impact of a compromise and may create avoidable privacy concerns.

Testing should confirm that the app requests only the permissions required for its functions. It should also examine whether personal data is collected, retained, displayed, or shared in ways that users may not expect.

How Android and iOS Risks Differ

Android and iOS use different security models, development tools, storage mechanisms, and application distribution processes. A professional assessment should follow platform-specific test cases rather than applying the same checklist without adjustment.

Security area Android considerations iOS considerations
Application package APK or app bundle analysis, exported components, manifest settings, signing, and debug configuration IPA and binary analysis, entitlements, provisioning, signing, and build configuration
Secure storage Android Keystore, encrypted storage, shared preferences, databases, logs, and backups Keychain configuration, data protection classes, local files, backups, and Secure Enclave use
App communication Intents, activities, services, content providers, broadcast receivers, and App Links URL schemes, universal links, extensions, pasteboard use, and associated domains
Device modification Behaviour on rooted devices, emulators, hooking tools, and integrity checks Behaviour on jailbroken devices, runtime instrumentation, and integrity protections
Permissions Manifest permissions, runtime permissions, exported components, and platform-version behaviour Entitlements, privacy permissions, capability access, and permission prompts

Both platforms provide strong built-in security features. However, these protections cannot compensate for insecure application logic or incorrect implementation.

What Mobile Application VAPT Should Examine?

The assessment should use the production-ready application build, or a build that closely represents what users will install. Where possible, testers should also receive accounts for different roles and enough information to identify intended security boundaries.

Testing may examine:

  • Local files, databases, caches, backups, logs, screenshots, notifications, and clipboard use
  • Authentication, session handling, biometric controls, logout behaviour, and account recovery
  • Encryption, certificate validation, network traffic, and protection against interception
  • Application permissions, exported components, deep links, URL schemes, and inter-app communication
  • Embedded secrets, debug functions, test endpoints, and sensitive information inside the application package
  • Reverse engineering, runtime manipulation, rooting or jailbreak checks, and integrity controls
  • WebViews, native bridges, third-party libraries, software development kits, and analytics components
  • Privacy-related data collection, tracking, device identifiers, and unnecessary platform access

The objective is not simply to list missing protections. Testers should determine whether a weakness can expose data, bypass a control, alter a transaction, or enable misuse of an important business function.

The App and Its Backend Must Be Tested Together

A mobile app rarely operates alone. It usually connects to APIs, identity services, databases, cloud platforms, payment providers, and analytics systems.

The app may securely protect information on the device while its backend accepts unauthorised requests. The reverse is also possible: the server may enforce strong permissions while the app exposes tokens, credentials, or sensitive records locally.

Testing should therefore follow important actions from the device to the supporting service. Where the application relies heavily on remote endpoints, the APIs supporting the mobile experience should receive appropriate security testing rather than being assumed secure because the app interface restricts access.

Apps built around managed databases, serverless functions, storage services, or cloud identity platforms may also require coordination with testing of the underlying cloud environment. Mobile VAPT should identify risks at the app boundary without repeating a complete cloud or API assessment.

Third-party software development kits also deserve attention. Advertising, analytics, payment, messaging, and customer-support SDKs may collect data or introduce functionality that the organisation did not develop directly.

When Should Businesses Prioritise Mobile Testing?

Mobile application VAPT should be considered when an organisation:

  • Prepares to release a new Android or iOS application
  • Adds payments, account management, document access, or other sensitive functions
  • Changes authentication, biometric login, deep links, or backend integrations
  • Introduces a major redesign or new development framework
  • Uses the app to process personal, financial, health, or confidential business data
  • Adds third-party SDKs or changes analytics, advertising, or payment providers
  • Discovers suspicious sessions, modified apps, automated abuse, or data leakage
  • Has not tested the application since several major releases or operating system changes

Testing before release gives development teams time to correct weaknesses before users install the app. Testing should also continue after significant changes because new code, platform features, and third-party components can alter the application’s exposure.

Android and iOS versions should both be assessed when their implementations differ. A control that works correctly on one platform may be missing or implemented differently on the other.

Final Thoughts: Test Security Beyond the App Screen

A polished mobile interface can hide serious weaknesses beneath the surface. Sensitive information may remain on the device, links may open protected functions, and application code may reveal secrets or security decisions to anyone willing to inspect it.

Mobile application VAPT examines the risks created when software leaves the organisation’s controlled environment and runs on customer or employee devices. It tests how the application protects data, communicates with the operating system, handles hostile input, and responds to reverse engineering or manipulation.

Aegixis VAPT Services can assess Android and iOS applications using platform-specific static and dynamic testing techniques. The assessment can cover local storage, authentication, communications, platform interaction, privacy controls, tampering risks, and the connection between the app and its supporting services.

By identifying weaknesses before they lead to data exposure, account misuse, fraud, or reputational damage, Aegixis helps organisations release and maintain mobile applications with greater security confidence.