mitigations.md

Mitigation Strategies Analysis for apollographql/apollo-android

Mitigation Strategy: Server-Side Query Complexity and Depth Limiting (with Client Awareness)

• Description:

  1. Documentation Review: Android developers, using apollo-android, review the documented limits provided by the backend team (regarding query complexity and depth).
  2. Client-Side Design: Design GraphQL queries within the apollo-android client (in .graphql files or programmatically) to stay within the server's defined limits. Avoid deeply nested or overly complex queries.
  3. Error Handling: Implement error handling in the apollo-android client to detect server responses indicating query complexity violations (typically a specific error code or message in the GraphQL error response). Use apollo-android's error handling mechanisms.
  4. User Feedback: When a complexity violation occurs, provide user-friendly feedback (e.g., "Your request is too complex. Please simplify it."). Do not expose raw error messages from the server.
  5. Testing: Write unit and integration tests using apollo-android that deliberately send complex queries to verify the server's enforcement and the client's error handling.

• Threats Mitigated:

  • Denial of Service (DoS) due to Complex Queries: (Severity: High) - Client-side awareness helps prevent sending queries that would be rejected by the server.
  • Resource Exhaustion: (Severity: Medium) - Client avoids sending unnecessarily resource-intensive queries.

• Impact:

  • DoS due to Complex Queries: Risk reduced. The client is designed to avoid triggering the issue.
  • Resource Exhaustion: Risk reduced. Client-side awareness helps minimize the likelihood of sending resource-intensive queries.

• Currently Implemented:

  • Error handling for GraphQL errors is implemented in NetworkClient.kt.
  • Basic query structure is defined in .graphql files.

• Missing Implementation:

  • Specific tests for query complexity violations are missing.
  • No explicit design considerations to minimize query complexity within the apollo-android client code.

Mitigation Strategy: Use Persisted Queries

• Description:

  1. Client-Side Integration: Configure the apollo-android client to use persisted queries. Instead of sending the full query string with each request, the client sends the identifier (hash or ID) of the pre-registered query. This requires using apollo-android's APIs for persisted queries.
  2. Automated Generation (with Client Integration): Integrate a tool (like apollo-tooling) into the Android build process. This tool should:
     • Automatically extract GraphQL queries from the project (e.g., from .graphql files).
     • Generate a manifest of persisted queries (mapping query strings to identifiers).
     • Potentially upload the manifest to the server (depending on the server's setup).
     • Configure apollo-android to use the generated manifest.

• Threats Mitigated:

  • Arbitrary Query Injection: (Severity: High) - The client cannot send arbitrary queries; it only sends pre-approved identifiers.
  • Reduced Attack Surface: (Severity: Medium) - The server only exposes a limited set of operations.

• Impact:

  • Arbitrary Query Injection: Risk almost entirely eliminated from the client-side perspective.
  • Reduced Attack Surface: Significant reduction in attack surface.

• Currently Implemented:

  • None. The project currently sends full query strings using apollo-android.

• Missing Implementation:

  • Entirely missing. Requires client-side changes and build process integration with apollo-android.

Mitigation Strategy: Secure Handling of GraphQL Errors

• Description:

  1. Error Parsing: Use apollo-android's error handling capabilities (e.g., ApolloCall.Callback, ApolloException) to parse GraphQL error responses. Extract relevant information (error code, message, extensions, path).
  2. Sanitization: Never directly display raw error messages from the server to the user. Sanitize the error information within the apollo-android client code, removing any potentially sensitive details.
  3. User-Friendly Messages: Create user-friendly error messages based on the parsed and sanitized error information. Provide helpful guidance to the user, appropriate for the application's context.
  4. Secure Logging: When logging errors for debugging within the apollo-android client, be extremely careful not to log sensitive data that might be present in the raw error response. Redact or remove any sensitive information before logging.
  5. Error Classification: Within the apollo-android client, differentiate between different types of GraphQL errors (e.g., validation errors, authorization errors, internal server errors) and handle them appropriately (different UI treatment, retry logic, etc.).

• Threats Mitigated:

  • Information Disclosure via Error Messages: (Severity: Medium) - Prevents leaking sensitive information through error messages displayed by the apollo-android client.
  • Improved User Experience: (Severity: Low) - Provides more helpful and less confusing error messages.

• Impact:

  • Information Disclosure: Risk significantly reduced. Raw error messages are not exposed by the client.
  • Improved User Experience: Positive impact on user experience.

• Currently Implemented:

  • Basic error parsing is done in NetworkClient.kt using apollo-android's APIs.

• Missing Implementation:

  • No sanitization of error messages before displaying them to the user within the apollo-android client.
  • No secure logging practices in place for error handling within the client.
  • No differentiation between different types of GraphQL errors within the client's error handling logic.

Mitigation Strategy: Secure Authentication Token Handling

• Description:

  1. Secure Storage: Use Android's Keystore system (or a similarly secure mechanism) to store authentication tokens. Do not store tokens in SharedPreferences, plain text files, or other insecure locations.
  2. Token Retrieval: Retrieve tokens from secure storage only when needed for a request.
  3. HTTP Headers: Use standard HTTP headers (e.g., Authorization: Bearer <token>) to include the token in requests to the GraphQL server. Use apollo-android's interceptor capabilities (e.g., addApplicationInterceptor) to add the authentication header to each request.
  4. Token Refresh: Implement a token refresh mechanism using apollo-android's interceptor capabilities. The interceptor should:
     • Check for token expiration before sending a request.
     • If the token is expired, attempt to refresh it (using a refresh token or other mechanism).
     • If the refresh is successful, update the stored token and retry the original request.
     • If the refresh fails, handle the authentication failure appropriately (e.g., redirect to login).
  5. Logout: When user logout, securely remove token from storage.

• Threats Mitigated:

  • Token Theft: (Severity: High) - Reduces the risk of attackers stealing authentication tokens.
  • Unauthorized Access: (Severity: High) - Prevents unauthorized access if a token is compromised or expired.

• Impact:

  • Token Theft: Risk significantly reduced by using secure storage.
  • Unauthorized Access: Risk reduced by proper token handling and refresh mechanisms, implemented using apollo-android's features.

• Currently Implemented:

  • Tokens are stored in SharedPreferences (INSECURE!).
  • HTTP headers are used for authentication via apollo-android's interceptors.

• Missing Implementation:

  • Secure storage using Android Keystore is not implemented.
  • Token refresh mechanism is not implemented using apollo-android's interceptor capabilities.

Mitigation Strategy: Client-Side Testing for Disabled Introspection

• Description:

  1. Test Environment: Set up a test environment that mimics the production environment, specifically with GraphQL introspection disabled on the server.
  2. Client-Side Tests: Write tests using apollo-android that attempt to perform introspection queries.
  3. Error Handling Verification: Ensure that the apollo-android client gracefully handles the errors that occur when introspection is disabled. Verify that the application functions correctly even without introspection.
  4. No reliance on introspection: Ensure that production code does not rely on introspection.

• Threats Mitigated:

  • Schema Exposure (Indirectly): (Severity: Medium) - Ensures the client doesn't break if introspection is disabled, supporting the server-side mitigation.
  • Reliance on Introspection: (Severity: Low) - Prevents the client from relying on a feature that may not be available.

• Impact:

  • Schema Exposure: Indirectly supports the server-side mitigation.
  • Reliance on Introspection: Prevents unexpected behavior in production.

• Currently Implemented:

  • None.

• Missing Implementation:

  • Client-side testing against an environment without introspection is not explicitly done.
  • Error handling for failed introspection attempts is not specifically implemented or tested within the apollo-android client.

Mitigation Strategy: Keep Dependencies Updated

• Description:

  1. Regular Updates: Regularly check for updates to the apollo-android library itself using Gradle. Update to the latest stable version.
  2. Vulnerability Scanning: Although this is a general practice, it directly impacts apollo-android. Use a vulnerability scanner to check for known vulnerabilities in apollo-android and its transitive dependencies.

• Threats Mitigated:

  • Known Vulnerabilities in apollo-android: (Severity: Variable, can be High) - Reduces the risk of exploiting known vulnerabilities in the apollo-android library.

• Impact:

  • Known Vulnerabilities: Risk significantly reduced by keeping apollo-android up-to-date.

• Currently Implemented:

  • Gradle is used for dependency management.

• Missing Implementation:

  • No regular, scheduled updates of the apollo-android library.
  • No vulnerability scanning specifically targeting apollo-android and its dependencies.