Threat: Unencrypted Data Storage on Disk
Description: MMKV, by default, stores data in unencrypted files on the device's file system. An attacker gaining physical access to the device can directly read these files using file explorer or command-line tools, exposing the stored data. Impact: Exposure of sensitive user data, application secrets, or confidential information stored in MMKV. This can lead to privacy breaches, identity theft, or unauthorized access to application functionalities. MMKV Component Affected: Core MMKV Storage Engine (default unencrypted storage). Risk Severity: High (if sensitive data is stored). Mitigation Strategies: * Enable MMKV encryption using a strong encryption key during MMKV initialization. * Minimize storing highly sensitive data in MMKV if possible. * Implement device-level security measures (screen lock, full disk encryption) as a defense-in-depth approach.
Threat: MMKV Library Bugs or Crashes
Description: Undiscovered bugs or vulnerabilities within the MMKV library code itself can be exploited or triggered, leading to application crashes, data corruption, or unexpected behavior. An attacker might craft specific inputs or usage patterns to trigger these vulnerabilities. Impact: Application unavailability, data access disruption, potential data corruption or loss, and in severe cases, potentially exploitable crashes leading to further security compromises. MMKV Component Affected: Core MMKV Library Code, potentially all modules depending on the bug. Risk Severity: High (in scenarios where bugs lead to data corruption, denial of service impacting critical functionality, or potential remote code execution if vulnerabilities are severe). Mitigation Strategies: * Use stable and well-tested versions of the MMKV library. * Regularly update MMKV library to the latest versions and apply security patches released by the maintainers. * Conduct thorough testing of the application, including robustness and edge case testing, to identify potential issues related to MMKV usage and report any found issues to the MMKV developers.
Description: When encryption is enabled in MMKV, improper handling of the encryption key can severely weaken or negate the encryption's security. This includes practices like hardcoding keys in the application, storing keys insecurely (e.g., in shared preferences without proper protection), using weak key derivation methods, or failing to protect the key during its lifecycle. If an attacker gains access to the poorly managed key, they can decrypt all MMKV data. Impact: Complete bypass of MMKV encryption, leading to full data confidentiality compromise. All data intended to be protected by encryption becomes accessible to the attacker. MMKV Component Affected: Encryption Module, Key Management (application-level implementation). Risk Severity: Critical (if encryption is intended to protect highly sensitive data and key management is flawed). Mitigation Strategies: * Use cryptographically secure methods for generating encryption keys. * Store encryption keys securely using platform-specific secure storage mechanisms like Android Keystore or iOS Keychain. Avoid storing keys in application code or easily accessible shared storage. * Implement proper key lifecycle management, including key rotation if necessary, and secure key derivation if deriving keys from user inputs.
Description: Developers might unintentionally or mistakenly misconfigure MMKV settings in a way that weakens security. A critical misconfiguration is disabling encryption when it is intended to protect sensitive data. This leaves the data stored in MMKV vulnerable to unauthorized access if the device is compromised. Impact: Data confidentiality compromise. Sensitive data intended to be protected by encryption is stored unencrypted, making it easily accessible to attackers with device access. MMKV Component Affected: MMKV Initialization, Configuration Settings. Risk Severity: High (if misconfiguration leads to unencrypted storage of sensitive data). Mitigation Strategies: * Carefully review and verify MMKV configuration settings, especially encryption settings, during development and deployment. * Enforce secure configuration practices through code reviews and automated configuration checks. * Clearly document and communicate the intended secure configuration of MMKV to the development team.