Mobile application security is the practice of protecting apps that run on phones and tablets from theft, tampering, misuse, and data exposure. It covers secure coding, authentication, encryption, runtime protections, permission control, and testing for weaknesses in the app, device, network, and backend services it connects to.
What mobile application security covers
Mobile application security focuses on the controls that keep phone and tablet apps trustworthy across their full lifecycle, from code and build time to runtime behaviour and backend interaction. It is not only about the app binary itself, but also the data, permissions, storage, and network paths the app depends on.
Because mobile apps sit in a consumer device environment, the security posture has to account for a more variable trust boundary than many server-side systems. A secure app may still expose data if it stores secrets unsafely, trusts local state too much, or fails open when device protections are weak.
Common attack surfaces and failure points
The most important failure points usually involve secret storage, authentication flows, local data exposure, insecure transport, and overly broad permissions. Mobile apps often touch multiple layers at once, which means one weak design choice can expose both device data and backend services.
Hardcoded credentials, weak token handling, insecure local caches, and missing certificate validation are recurring causes of compromise. The same is true for permission misuse: an app may request more device access than it genuinely needs, creating a larger blast radius if the app is abused or reversed engineered.
- Secrets embedded in code or configuration can be extracted from the package.
- Poor session handling can let attackers reuse tokens after compromise.
- Weak transport security can expose traffic to interception or tampering.
- Unsafe permission use can reveal contacts, location, photos, or device identifiers.
Secure design and runtime protections
Strong mobile security combines secure coding with platform-aware hardening. That typically includes minimising sensitive data on the device, using OS-backed storage where possible, validating backend trust carefully, and treating the mobile client as an exposed environment rather than a trusted one.
Runtime protections matter because mobile apps are frequently inspected, repackaged, instrumented, or run on rooted or jailbroken devices. Defensive measures such as integrity checks, anti-tamper controls, and sensible error handling reduce the value of a modified client, but they work best when the backend also enforces authorisation and request validation.
Testing should include both static and dynamic review, plus checks for insecure dependencies, exposed APIs, and weak client-side assumptions. The app may look secure in isolation and still fail when connected services are permissive or when local storage and logging leak sensitive material.
How it relates to broader application and data security
Mobile application security is a specialised branch of application security, but its outcomes extend into identity, access, and data protection because mobile apps authenticate users, hold session material, and broker access to backend services. For baseline web and API control expectations, OWASP ASVS is a useful companion reference, especially for authentication, session management, and authorization.
Mobile security also inherits many of the same exposure patterns seen in API abuse and secret leakage. When an app depends on backend APIs, weaknesses in client code can become a direct path to account misuse, data exfiltration, or service abuse even if the server-side logic is otherwise well built.
For practitioners, the key question is whether the app fails safely when the device, network, or client code cannot be trusted. That is why mobile security is really a combined control problem across code, platform, backend, and user data, not just a single app hardening exercise.
Risk and Threat Considerations
Mobile apps are attractive targets because they often contain reusable credentials, session tokens, personal data, and direct pathways into backend services. When those controls are weak, an attacker can move from app compromise to account abuse, data theft, or fraudulent API use without needing to break the backend first.
Failure mechanism: Attackers commonly exploit hardcoded secrets, insecure local storage, weak token handling, permissive permissions, or poor transport validation to extract data or impersonate the app against its services.
Impact: The result can include account takeover, exposure of sensitive user data, manipulation of business transactions, and broader compromise of the services the app can reach.
Standards & Framework Alignment
This section maps relevant standards and security frameworks to the operational risks and controls described in this guidance.
OWASP API Security Top 10 addresses the attack surface, OWASP ASVS and NIST SP 800-53 Rev 5 set the technical controls, and ISO/IEC 27001:2022 defines the regulatory obligations.
| Framework | Control / Reference | Relevance |
|---|---|---|
| OWASP ASVS | V6 — Authentication | Mobile apps rely on authenticated sessions and login flows. |
| V7 — Session Management | Mobile clients often store and reuse session material across device and backend interactions. | |
| V8 — Authorization | Mobile apps must not trust client-side decisions for access to user data or backend functions. | |
| Recommendation — Apply V6 to verify mobile authentication strength, session handling, and re-authentication paths. Apply V7 to reduce token exposure and constrain session reuse after compromise. Apply V8 to enforce server-side authorization for every mobile app action. | ||
| NIST SP 800-53 Rev 5 | AC-6 — Least Privilege | Mobile apps should request and use only the permissions and access they truly need. |
| SC-13 — Cryptographic Protection | Mobile app security depends on protecting data and traffic with strong cryptography. | |
| SI-7 — Software, Firmware, and Information Integrity | Mobile apps face tampering, repackaging, and runtime integrity threats. | |
| Recommendation — Apply AC-6 to minimise app and backend privilege, reducing blast radius if the client is abused. Use SC-13 to protect mobile data in transit and sensitive material handled by the app. Use SI-7 to detect tampering and validate app and update integrity. | ||
| ISO/IEC 27001:2022 | A.8.24 — Use of cryptography | Mobile apps depend on cryptographic protection for stored data and communications. |
| A.8.25 — Secure development life cycle | Mobile app security is built into secure coding, testing, and release practices. | |
| Recommendation — Apply A.8.24 to protect mobile data and communications with approved cryptographic controls. Apply A.8.25 to embed mobile security requirements into development and release workflows. | ||
| OWASP API Security Top 10 | API2 — Broken Authentication | Mobile apps often authenticate to APIs, and weak client flows expose those services. |
| API5 — Broken Function Level Authorization | Mobile apps frequently expose backend functions that must be protected server-side. | |
| Recommendation — Use API2 to test mobile-to-API authentication and token handling. Use API5 to enforce function-level authorization for all app-triggered actions. | ||
Practitioner Guidance
Why practitioners should care: Mobile security decisions are rarely isolated to the client. A mobile app that stores secrets badly or overtrusts local state can undermine backend controls, even when server-side engineering is strong.
What to watch for: Treat secret storage, authentication, permission scope, and network trust as the highest-value review points. If an app can still function after credentials are exposed from the package or from device storage, the design usually needs a deeper control review.
Practitioner takeaway: The most durable mobile security posture comes from assuming the app is inspectable and the device is semi-trusted, then enforcing critical trust decisions on the backend rather than in the client.
Related resources from NHI Mgmt Group
- How do access reviews improve mobile application security?
- What do security teams get wrong about mobile and application secrets?
- How should security teams apply OWASP Mobile Application Security standards in practice?
- Why do mobile apps create blind spots in application security programmes when testing is mostly manual?
