Attack Surface: Shared Code Vulnerabilities (Amplified Impact)
- Description: Flaws in the code shared across all platforms (
commonMain
). The amplified impact is the key Compose Multiplatform-specific aspect. - Compose Multiplatform Contribution: Code sharing is the core of Compose Multiplatform. A single vulnerability affects all target platforms (Android, iOS, Desktop, Web), making this a significantly higher risk than platform-specific vulnerabilities.
- Example: A flawed authentication bypass in the shared logic would allow unauthorized access on all platforms. A data validation error could lead to data corruption across all platforms.
- Impact: Compromise of application data, functionality, and user accounts across all platforms. Data breaches, unauthorized access, denial of service.
- Risk Severity: Critical (if affecting authentication, authorization, or critical data) / High (for most other shared logic flaws).
- Mitigation Strategies:
- Rigorous Code Review (Multiplatform Focus): Multiple reviewers, each with expertise in different platform security, must review the shared code.
- Centralized, Robust Input Validation: Assume all input is malicious. Implement strong input validation and output encoding in the shared code.
- Secure Dependency Management (Shared Dependencies): Use dependency scanning tools (e.g., OWASP Dependency-Check, Snyk) and regularly audit shared dependencies.
- Static Analysis (Multiplatform Configuration): Configure static analysis tools to specifically target Kotlin Multiplatform code and common vulnerabilities.
- Fuzz Testing (Shared Code): Apply fuzzing to the shared code to uncover edge cases and unexpected vulnerabilities.
- Comprehensive Unit/Integration Tests (Security-Focused): Include security-specific test cases in the shared code's test suite.
Attack Surface: Inconsistent expect
/actual
Implementations
- Description: Security-relevant differences in behavior between platform-specific implementations (
actual
) of a shared interface (expect
). - Compose Multiplatform Contribution: The
expect
/actual
mechanism is fundamental to Compose Multiplatform's platform abstraction. Inconsistencies create platform-specific vulnerabilities that bypass the shared code's intended security. - Example: An
expect
function for secure storage might have anactual
implementation on Android that uses encrypted SharedPreferences, but the iOSactual
implementation might mistakenly use unencrypted UserDefaults, leading to data leakage on iOS. - Impact: Platform-specific vulnerabilities that circumvent the shared code's security controls. Privilege escalation, data leaks, or other platform-specific exploits.
- Risk Severity: High (potential for significant platform-specific compromise, bypassing shared security).
- Mitigation Strategies:
- Precise
expect
Interface Definition: Theexpect
declaration must explicitly define all security requirements and expected behavior. - Cross-Platform Code Review: Reviewers must compare
actual
implementations side-by-side, looking for any behavioral differences, not just functional ones. - Platform-Specific Security Tests: Create separate test suites for each
actual
implementation, verifying its security behavior against theexpect
definition. - Documentation of Security Assumptions: Clearly document all security-related assumptions and requirements for each
actual
implementation.
- Precise
Attack Surface: Unsafe Native Interoperability (Through Shared or actual
Code)
- Description: Vulnerabilities arising from interactions between Kotlin code (either shared or in
actual
implementations) and native code (C/C++, Objective-C, Swift, etc.). - Compose Multiplatform Contribution: Compose Multiplatform uses Kotlin/Native for interoperability with platform-specific APIs and libraries. This necessitates native interop, introducing the inherent risks.
- Example: A shared Kotlin function uses Kotlin/Native to call a C library for cryptographic operations. If the C library has a vulnerability (e.g., a buffer overflow), it can be triggered through the shared Kotlin code, affecting all platforms. Alternatively, an
actual
implementation might use a vulnerable native library specific to that platform. - Impact: Memory corruption, arbitrary code execution, denial of service, and other classic native code vulnerabilities. Potential for complete system compromise.
- Risk Severity: Critical / High (depending on the nature and extent of the native interaction).
- Mitigation Strategies:
- Minimize Native Interop: Prefer platform-specific Kotlin APIs whenever possible to reduce the reliance on native code.
- Memory Safety (Kotlin/Native): Use Kotlin's memory management features meticulously when interacting with native code. Avoid manual memory management in Kotlin/Native if at all possible.
- Secure Coding Practices (Native Code): If writing native code, adhere strictly to secure coding guidelines for the chosen language (e.g., C/C++). Consider memory-safe languages (e.g., Rust) where feasible.
- Auditing of Native Libraries: Thoroughly vet all third-party native libraries used (both shared and platform-specific) for security vulnerabilities.
- Input Validation (Before Native Calls): Rigorously validate all data passed to native code from Kotlin.
- Sandboxing: If possible, sandbox native code.
Attack Surface: Compose Runtime Exploits
- Description: Vulnerabilities within the Compose runtime library itself.
- Compose Multiplatform Contribution: Compose Multiplatform uses a custom runtime, which is a direct attack vector.
- Example: A hypothetical vulnerability in state management could allow UI manipulation or data leaks. A DoS could be triggered by forcing excessive recomposition.
- Impact: UI manipulation, data leaks, DoS, potentially arbitrary code execution (in severe, unlikely cases).
- Risk Severity: High.
- Mitigation Strategies:
- Keep Compose Updated: This is the primary mitigation. Regularly update to the latest Compose Multiplatform version to get security patches.
- Monitor Security Advisories: Subscribe to JetBrains' security advisories for Compose.
- Avoid Excessive Complexity: While not a complete solution, limiting extremely complex UI interactions can reduce the attack surface within the runtime.
Attack Surface: Deserialization issues in shared code
- Description: Vulnerabilities arising from deserialization of untrusted data in shared code.
- Compose Multiplatform Contribution: If shared code is using kotlinx.serialization, there is a risk of Deserialization vulnerabilities.
- Example: Application is using kotlinx.serialization to deserialize data from untrusted source. Attacker can send malicious data that will be deserialized and executed.
- Impact: Arbitrary code execution.
- Risk Severity: Critical.
- Mitigation Strategies:
- Avoid deserialization of untrusted data: If possible, avoid deserialization of untrusted data.
- Use allow lists: If deserialization of untrusted data is necessary, use allow lists to restrict which classes can be deserialized.
- Validate data after deserialization: Validate data after deserialization to ensure that it is valid.
- Use secure deserialization libraries: Use secure deserialization libraries that are not vulnerable to deserialization attacks.