threat-modeling.md

Threat Model Analysis for baseflow/flutter-permission-handler

Threat: Permission Request Spoofing/Bypassing

• Threat: Permission Request Spoofing/Bypassing
  • Description: A malicious app on the same device exploits vulnerabilities within the flutter-permission-handler plugin itself or its interaction with the OS permission system to obtain permissions without proper user consent. This is distinct from general OS-level spoofing; this focuses on flaws specific to the plugin's implementation. This might involve:
    • Exploiting race conditions in the plugin's native code bridges.
    • Manipulating the plugin's internal state to bypass permission checks.
    • Finding flaws in how the plugin handles responses from the OS permission dialog.
    • Injecting code that directly interacts with the plugin's functions, rather than the OS APIs.
  • Impact: The malicious app gains unauthorized access to sensitive user data or device functionality, bypassing the intended security mechanisms of both the plugin and the OS. This could lead to severe privacy violations, data theft, or device compromise.
  • Affected Component:
    • requestPermissions() function (and its platform-specific implementations within the plugin).
    • Native code bridges (Android: Java/Kotlin; iOS: Objective-C/Swift) specifically within the plugin's code.
    • Internal state management of permission requests within the plugin.
  • Risk Severity: Critical
  • Mitigation Strategies:
    • Developer:
      • Always use the requestPermissions() function as provided by the plugin. Do not attempt to modify its behavior or create custom wrappers that might introduce vulnerabilities.
      • Validate the returned permission status after the request, using the plugin's provided methods.
      • Keep the flutter-permission-handler plugin updated to the latest version to receive security patches.
      • Implement robust error handling for permission request failures, specifically checking for error codes returned by the plugin.

Threat: Incorrect Permission Status Reporting

• Threat: Incorrect Permission Status Reporting
  • Description: The flutter-permission-handler plugin itself contains bugs that cause it to incorrectly report the status of a permission. This is not about the OS reporting incorrectly, but about the plugin misinterpreting or misrepresenting the OS response. Examples:
    • A bug in the plugin's logic causes it to report PermissionStatus.granted when the OS actually returned PermissionStatus.denied.
    • The plugin fails to correctly parse the response from the OS permission system due to a coding error.
    • Internal caching within the plugin is flawed, leading to stale or incorrect status reports.
  • Impact: The application relies on incorrect information from the plugin, leading to attempts to access resources without permission (crashing or exposing data) or failing to use resources that are permitted.
  • Affected Component:
    • checkPermissionStatus() function (and its platform-specific implementations within the plugin).
    • Internal caching or state management of permission status within the plugin.
  • Risk Severity: High
  • Mitigation Strategies:
    • Developer:
      • Thoroughly test checkPermissionStatus() under all possible permission states, focusing on edge cases and potential inconsistencies between the plugin's reporting and the actual OS state.
      • Implement robust error handling that gracefully handles unexpected permission status values returned by the plugin.
      • Do not rely solely on cached permission status within the application; periodically re-check using the plugin's checkPermissionStatus() function.

Threat: Vulnerability in Native Code Implementation

• Threat: Vulnerability in Native Code Implementation
  • Description: The flutter-permission-handler plugin's own native code (Java/Kotlin for Android, Objective-C/Swift) contains security vulnerabilities that can be directly exploited. This is not about general OS vulnerabilities, but about flaws within the plugin's code. Examples:
    • Buffer overflows in the plugin's native code that handles permission requests or responses.
    • Logic errors in the plugin's native code that allow for permission escalation through the plugin.
    • Vulnerabilities in the plugin's handling of inter-process communication (IPC) if the plugin uses IPC internally.
  • Impact: A malicious app could exploit these vulnerabilities in the plugin to gain unauthorized access to permissions, bypass security checks implemented by the plugin, or potentially execute arbitrary code within the context of the application using the plugin.
  • Affected Component:
    • The platform-specific implementations of the plugin (the native code within the plugin itself).
    • The communication bridge between the Flutter code and the native code within the plugin.
  • Risk Severity: Critical
  • Mitigation Strategies:
    • Developer:
      • Keep the flutter-permission-handler plugin updated to the latest version. This is the primary defense, as the plugin maintainers are responsible for fixing vulnerabilities in their code.
      • Monitor security advisories specifically related to the flutter-permission-handler plugin.
      • If you have expertise in native code security, consider reviewing the plugin's source code for potential vulnerabilities (it's open source).
      • Report any suspected vulnerabilities to the plugin maintainers immediately.

Threat: Dependency Hijacking/Supply Chain Attack

• Threat: Dependency Hijacking/Supply Chain Attack
  • Description: An attacker compromises the flutter-permission-handler plugin's repository or the pub.dev package distribution channel and replaces the legitimate plugin with a malicious version. This malicious version is specifically designed to compromise applications that use it.
  • Impact: The attacker gains complete control over the permissions requested by any application using the compromised plugin, leading to data theft, privacy violations, or device compromise. The malicious plugin could bypass all security checks.
  • Affected Component: The entire flutter-permission-handler plugin.
  • Risk Severity: Critical
  • Mitigation Strategies:
    • Developer:
      • Use a pubspec.lock file to pin the exact version of the flutter-permission-handler plugin and all its dependencies. This prevents automatic updates to potentially compromised versions.
      • Regularly review the pubspec.lock file and update dependencies cautiously, researching any changes.
      • Consider using a private package repository with stricter access controls and auditing for your dependencies.
      • Monitor for security advisories specifically related to the flutter-permission-handler plugin and its dependencies.