mitigations.md

Mitigation Strategies Analysis for doctrine/instantiator

Mitigation Strategy: Strict Input Validation and Type Hinting (Pre-Instantiation)

• Description:

  1. Define a Whitelist: Create a configuration file or a dedicated class that maintains a list of fully qualified class names that are explicitly allowed to be instantiated using doctrine/instantiator. This list should be as restrictive as possible.
  2. Validate Class Name: Before calling $instantiator->instantiate($className), check if $className exists within the whitelist. Use a strict comparison (in_array($className, $whitelist, true)).
  3. Check Class Existence: Use class_exists($className) to verify that the class actually exists. This prevents attempts to instantiate non-existent classes before passing the name to Instantiator.
  4. Type Hinting and Reflection (Optional but Recommended): If possible, use reflection (new \ReflectionClass($className)) to further inspect the class before passing it to Instantiator. You might check if it implements a specific interface or extends a particular base class.
  5. Centralized Instantiation Logic: Encapsulate the instantiation logic (whitelist check, class_exists, reflection, and the Instantiator call) within a single factory method or dedicated service.
  6. Error Handling: If validation fails, throw an exception or log the attempt. Never proceed with $instantiator->instantiate() if validation fails.

• List of Threats Mitigated:

  • Arbitrary Class Instantiation (Critical): Prevents attackers from using Instantiator to create any class.
  • Denial of Service (DoS) (High): Limits Instantiator's ability to create resource-intensive classes.
  • Code Injection (Critical): Prevents Instantiator from being used with injected malicious class names.

• Impact:

  • Arbitrary Class Instantiation: Risk reduced from Critical to Low.
  • Denial of Service: Risk reduced from High to Medium.
  • Code Injection: Risk reduced from Critical to Low.

• Currently Implemented:

  • App\Factory\DataObjectFactory::create(): Implements whitelist and class_exists().
  • App\Service\LegacyDataImporter: Does not implement validation.

• Missing Implementation:

  • App\Service\LegacyDataImporter: Needs refactoring.
  • Whitelist in DataObjectFactory should be in a config file.
  • Reflection checks are not implemented.

Mitigation Strategy: Post-Instantiation Validation and Initialization

• Description:

  1. Define an Initialization Method: For every class instantiated with doctrine/instantiator, create a public method (e.g., initialize()).
  2. Mandatory Call: Immediately after calling $instantiator->instantiate($className), call the initialization method on the object.
  3. Property Validation: Inside the initialization method, validate all relevant object properties.
  4. Default Values: Set default values for properties not provided during initialization.
  5. Security Checks: Perform security checks that would normally be in the constructor.
  6. Exception Handling: If validation/security checks fail, throw an exception. Do not allow the object to be used.
  7. Interface (Optional): Consider a common interface (e.g., InitializableInterface) requiring the initialize() method.

• List of Threats Mitigated:

  • Use of Uninitialized Objects (High): Prevents using objects with uninitialized properties.
  • Bypassing Security Checks (Critical): Ensures security checks are executed, even with a bypassed constructor.
  • Data Corruption (Medium): Validates property values, mitigating data corruption.
  • Logic Errors (Medium): Consistent initialization prevents logic errors.

• Impact:

  • Use of Uninitialized Objects: Risk reduced from High to Low.
  • Bypassing Security Checks: Risk reduced from Critical to Low.
  • Data Corruption: Risk reduced from Medium to Low.
  • Logic Errors: Risk reduced from Medium to Low.

• Currently Implemented:

  • App\Model\DataObject: Implements initialize(), called after instantiation via DataObjectFactory.
  • App\Model\LegacyEntity: Has hydrate(), but not consistently called.

• Missing Implementation:

  • App\Service\LegacyDataImporter: Doesn't consistently call hydrate() on LegacyEntity.
  • No common interface (e.g., InitializableInterface) is used.
  • Not all classes instantiated via Instantiator have an initialization method.

Mitigation Strategy: Logging of Instantiator Use

• Description:

  1. Log Every Call: Directly within the code where $instantiator->instantiate($className) is called, add a logging statement.
  2. Detailed Information: The log entry must include:
     • The fully qualified $className.
     • The context (calling function, user ID, request ID, etc.).
     • Any input data used to determine $className.
  3. Error Handling: If an exception is caught during the instantiation process (either before or after the Instantiator call), log the exception details along with the class name and context.

• List of Threats Mitigated:

  • Detection of Exploits (Variable): Provides visibility into how Instantiator is being used, aiding in detecting attacks.
  • Auditing and Forensics (High): Enables investigation of security incidents specifically related to object instantiation.

• Impact:

  • Detection: Improves the ability to detect and respond to attacks that leverage Instantiator.
  • Investigation: Facilitates post-incident analysis.

• Currently Implemented:

  • General application logging exists, but no specific tracking of Instantiator calls.

• Missing Implementation:

  • Specific logging for each $instantiator->instantiate() call needs to be added.