attack-surface.md

Attack Surface Analysis for tonesto7/nest-manager

Attack Surface: OAuth 2.0 Authorization Code Flow

• 1. OAuth 2.0 Authorization Code Flow:

  • Description: The process of obtaining authorization from the user to access their Nest account via Google's OAuth 2.0. This is entirely within nest-manager's control.
  • nest-manager Contribution: nest-manager initiates, manages, and is responsible for the security of the entire OAuth 2.0 flow, including redirect URI handling, client secret protection, and authorization code exchange.
  • Example: An attacker intercepts the authorization code due to a vulnerability in nest-manager's handling of the redirect URI (e.g., insufficient validation).
  • Impact: Complete control of the user's Nest devices (thermostat, cameras, locks, etc.), leading to potential physical intrusion, privacy violation, or property damage.
  • Risk Severity: Critical
  • Mitigation Strategies:
    • (Developer) Rigorously validate the redirect_uri against a hardcoded, absolute whitelist. Reject any request with a redirect_uri that doesn't exactly match the expected value.
    • (Developer) Securely store the client secret using environment variables or a dedicated secrets management solution. Never include the secret in the source code or configuration files that might be exposed.
    • (Developer) Implement robust error handling and logging around the OAuth 2.0 flow, but absolutely never log sensitive data like tokens or the client secret. Log only enough information to diagnose issues without compromising security.

Attack Surface: Access/Refresh Token Storage and Handling

• 2. Access/Refresh Token Storage and Handling:

  • Description: The secure storage and management of the access and refresh tokens obtained from the Nest API. nest-manager is fully responsible for this.
  • nest-manager Contribution: nest-manager receives, stores, and uses these tokens for all API interactions. Its security practices directly determine the risk.
  • Example: nest-manager stores tokens in an unencrypted file, and an attacker with local access to the server (or through a separate vulnerability) retrieves them.
  • Impact: Unauthorized access to the user's Nest devices, with the same consequences as an OAuth 2.0 compromise.
  • Risk Severity: Critical
  • Mitigation Strategies:
    • (Developer) Encrypt tokens at rest using a strong, industry-standard encryption algorithm (e.g., AES-256). Securely manage the encryption key, separately from the encrypted tokens.
    • (Developer) Store tokens in a secure location designed for secrets management. Avoid plain text files, easily accessible databases, or configuration files. Consider using a dedicated secrets vault.
    • (Developer) Implement a token revocation mechanism. Provide a way for users to revoke tokens (e.g., through a web interface or command-line tool), and automatically revoke tokens upon detecting suspicious activity or after a defined period of inactivity.
    • (Developer) Ensure that token expiration is handled correctly. The application should gracefully handle expired tokens and attempt to refresh them securely, without exposing the user to errors or security risks.

Attack Surface: Vulnerable Dependencies

• 3. Vulnerable Dependencies:

  • Description: Third-party libraries (Node.js packages) used by nest-manager that contain known security vulnerabilities.
  • nest-manager Contribution: nest-manager's choice of dependencies and its update practices directly determine its exposure to this risk.
  • Example: A library used by nest-manager for making HTTP requests has a known remote code execution vulnerability.
  • Impact: Varies depending on the specific vulnerability in the dependency, but could range from denial of service to complete server compromise and subsequent access to Nest devices.
  • Risk Severity: High to Critical (depending on the vulnerability)
  • Mitigation Strategies:
    • (Developer) Regularly use dependency analysis tools (e.g., npm audit, snyk, Dependabot) to automatically identify and update vulnerable packages. Integrate these tools into the CI/CD pipeline.
    • (Developer) Maintain a Software Bill of Materials (SBOM) to track all dependencies and their versions.
    • (Developer) Carefully evaluate the security posture of any new dependency before adding it to the project. Consider the library's popularity, maintenance activity, and known security history.
    • (Developer): Consider using a dependency vulnerability scanner that integrates with your source code repository and provides alerts for newly discovered vulnerabilities.

Attack Surface: Data Validation and Sanitization (from Nest API)

• 4. Data Validation and Sanitization (from Nest API):

  • Description: Ensuring that data received from the Nest API is properly validated and sanitized to prevent injection or other data-related vulnerabilities. While the Nest API is generally trusted, nest-manager should still practice defensive programming.
  • nest-manager Contribution: nest-manager is responsible for parsing and processing all data received from the Nest API.
  • Example: Although unlikely, a compromised Nest API (or a sophisticated man-in-the-middle attack) could send malformed data that exploits a vulnerability in nest-manager's parsing logic.
  • Impact: Potentially code execution, denial of service, or data corruption within nest-manager. The likelihood is lower than with user-supplied input, but the impact could still be significant.
  • Risk Severity: High
  • Mitigation Strategies:
    • (Developer) Validate the structure and data types of all data received from the Nest API. Use schema validation (e.g., JSON Schema) if possible.
    • (Developer) Use well-established and actively maintained libraries for parsing data from the Nest API, rather than writing custom parsing code.
    • (Developer) Implement robust error handling to gracefully handle unexpected or malformed data from the API, without crashing or exposing sensitive information.