attack-surface.md

Attack Surface Analysis for doctrine/inflector

Attack Surface: Security Mechanism Bypass (Due to Direct Output Use)

• Description: An attacker manipulates input specifically crafted for Inflector functions to bypass security checks that incorrectly and directly rely on Inflector's output (e.g., authorization based on class names generated by Inflector, routing based on slugs generated by Inflector). This is a direct attack because the vulnerability stems from the application's reliance on the unvalidated output of Inflector itself in security logic.
• How Inflector Contributes: The application directly uses the output of Inflector functions (like classify, tableize, slug) within security-critical logic (authorization, routing, data access control) without proper validation or indirection. This makes the security mechanism dependent on the predictable, but manipulable, transformations of Inflector.
• Example:
  • Authorization Bypass: An application checks user permissions based on Inflector::classify($controllerName). An attacker provides a carefully chosen $controllerName (e.g., "AdminPanel" instead of "UserPanel") that, when processed by Inflector, results in a class name that grants unauthorized access. The attack works because the security check directly uses the Inflector::classify output.
  • Routing Bypass: An application uses Inflector::tableize($resourceName) to determine the database table to query. An attacker provides a $resourceName (e.g., "users; DROP TABLE users --") that, when processed by Inflector, might be concatenated directly into a SQL query, leading to SQL injection. (This highlights the combination of direct use and lack of output sanitization).
• Impact: Unauthorized access to resources or functionality, potentially leading to data breaches, privilege escalation, or complete system compromise.
• Risk Severity: High to Critical.
• Mitigation Strategies:
  • Indirection is Key: Never use Inflector output directly in security checks. Instead, use Inflector to generate a key or identifier. This key should then be looked up in a separate, secure, and controlled data structure (e.g., a permission map, a routing table, an ACL). The security decision should be based on this lookup, not on the raw Inflector output.
  • Strict Input Validation (Pre-Inflector): Rigorous input validation before data reaches Inflector is crucial. Define strict rules for the allowed format, length, and character set of the input. This limits the attacker's ability to control the output of Inflector.
  • Output Validation/Sanitization (Post-Inflector): Even after using Inflector to generate a key, validate that key against a whitelist or other secure mechanism before using it in any security-related operation. This is a defense-in-depth measure.
  • Principle of Least Privilege: Ensure that users and application components have only the minimum necessary permissions. This limits the damage from a successful bypass.
  • Example of Correct Usage:

    // BAD (Vulnerable):
    $className = Inflector::classify($userInput);
    if (class_exists($className) && userHasAccessToClass($className)) { ... }
    
    // GOOD (More Secure):
    $resourceKey = Inflector::classify($userInput); // Use Inflector for key generation
    if (isset($allowedResources[$resourceKey]) && userHasAccessToResource($resourceKey)) { ... }
    // $allowedResources is a predefined, secure array mapping keys to resources.