threat-modeling.md

Threat Model Analysis for slimphp/slim

Threat: Dependency Hijacking (Supply Chain Attack)

• Description: An attacker compromises a package that Slim itself depends on (e.g., a PSR-7 implementation). The attacker injects malicious code into the dependency. When Slim or an application using Slim updates its dependencies, the malicious code is executed. This is a direct threat because Slim's functionality relies on these external dependencies.
  • Impact: Remote Code Execution (RCE), data exfiltration, complete system compromise, denial of service.
  • Affected Slim Component: Indirectly affects the entire application, as any part of Slim could use the compromised dependency. Specifically impacts the composer dependency management system and any Slim code that utilizes the compromised dependency.
  • Risk Severity: Critical
  • Mitigation Strategies:
    • Use a dependency vulnerability scanner (composer audit, Snyk, Dependabot) and address reported vulnerabilities promptly.
    • Regularly update dependencies (composer update).
    • Carefully vet new dependencies before adding them (though this is less directly applicable to Slim's dependencies, as those are largely fixed).
    • Consider using a Software Composition Analysis (SCA) tool.
    • Pin dependencies to specific versions (using composer.lock) after thorough testing, but be aware this can prevent security updates. A balance is needed. This is more applicable to application-level dependencies than Slim's core dependencies.
    • Use a private package repository (e.g., Private Packagist, Artifactory) to control the source of dependencies (again, more applicable to application dependencies).

Threat: Middleware Ordering Bypass

• Description: An attacker crafts a request that exploits an incorrect middleware ordering within Slim's middleware pipeline. If authentication middleware is placed after authorization middleware, the attacker can bypass authorization. This is a direct Slim issue because the framework provides the middleware mechanism and its ordering is crucial for security.
  • Impact: Unauthorized access to protected resources, data breaches, bypassing security controls.
  • Affected Slim Component: The App object's middleware pipeline (->add(), ->addMiddleware()). The specific impact depends on the misconfigured middleware.
  • Risk Severity: High
  • Mitigation Strategies:
    • Carefully plan and document the middleware execution order. Understand the dependencies between middleware components.
    • Thoroughly test the middleware pipeline with various request types to ensure the correct order is enforced.
    • Use automated tests to verify that security-critical middleware executes before any middleware that depends on it.
    • Consider using a visual tool or diagram to represent the middleware pipeline.

Threat: Third-Party Middleware Vulnerability (Specifically in Slim Middleware)

• Description: An attacker exploits a known vulnerability in a third-party Slim middleware package used by the application. This is distinct from a general dependency issue because it's specific to middleware that integrates directly with Slim's request/response cycle.
  • Impact: Varies depending on the vulnerability in the middleware, potentially RCE, data leakage, DoS.
  • Affected Slim Component: The specific third-party middleware component (implementation of MiddlewareInterface) that integrates with Slim's pipeline.
  • Risk Severity: High to Critical (depending on the vulnerability)
  • Mitigation Strategies:
    • Carefully vet third-party Slim middleware before using it. Research its security history and reputation.
    • Regularly update third-party Slim middleware to the latest versions.
    • Monitor security advisories related to the Slim middleware used.
    • Consider contributing to the security of the middleware by reporting vulnerabilities or submitting patches.

Threat: Information Leakage via Default Error Handling (in Production)

• Description: An attacker triggers an error, and Slim's default development error handler is accidentally left enabled in a production environment. This handler reveals sensitive information (file paths, stack traces) that aids the attacker. This is a direct Slim issue because it's the framework's default behavior.
  • Impact: Information disclosure, which can be used to facilitate other attacks.
  • Affected Slim Component: Slim\Error\Renderers\HtmlErrorRenderer (default in development), Slim\App::handleError.
  • Risk Severity: High
  • Mitigation Strategies:
    • Never use the default development error handler in a production environment.
    • Implement a custom error handler that displays generic error messages to users and logs detailed error information securely.
    • Configure Slim to use a production-ready error handler (e.g., ErrorHandler with appropriate settings, or a custom implementation).

Threat: Unprotected Internal Routes (Due to Misconfiguration of Slim's Routing)

• Description: Routes intended for internal use are exposed publicly due to a misconfiguration within Slim's routing setup, specifically a lack of proper middleware to protect them. This is a direct Slim issue because the routing configuration is managed by Slim.
  • Impact: Unauthorized access to sensitive functionality or data, potential for complete system compromise.
  • Affected Slim Component: Slim\Routing\RouteCollector, Slim\App::map, and any middleware intended for authentication/authorization but misconfigured or missing.
  • Risk Severity: High to Critical
  • Mitigation Strategies:
    • Use middleware to restrict access to internal routes based on user roles, IP addresses, or other criteria, ensuring this middleware is correctly placed in Slim's pipeline.
    • Implement strong authentication and authorization mechanisms for all internal routes.
    • Clearly separate internal and external routes in the application's code and configuration within Slim's routing setup.
    • Regularly review the route configuration within Slim to ensure that no internal routes are accidentally exposed.