attack-tree.md

Attack Tree Analysis for doctrine/instantiator

Objective: Execute Arbitrary Code or Access Sensitive Data via Doctrine Instantiator [CRITICAL]

Attack Tree Visualization

                                      Execute Arbitrary Code or Access Sensitive Data
                                      via Doctrine Instantiator [CRITICAL]
                                                  |
                                    -----------------------------------
                                    |
                      **Manipulate Instantiation Logic**
                                    |
                      -----------------------------------
                      |                                 |
      **1. Inject Malicious          3. Exploit Deserialization
         Class Name [CRITICAL]       Vulnerabilities [CRITICAL]
                                                  |
                                          ---------------------
                                          |
                                  9. Supply Unexpected
                                     Arguments to __wakeup
                                     (if used) [CRITICAL]

Attack Tree Path: 1. Inject Malicious Class Name [CRITICAL]

• Description: The attacker provides a class name that the application doesn't expect, aiming to instantiate a class with malicious side effects (e.g., in its constructor, although Instantiator bypasses this, or in a __wakeup method if deserialization is involved). The attacker might target:
  • A class within the application's codebase that performs sensitive operations when instantiated.
  • A known vulnerable class from a third-party library included in the project.
  • A class that, while not inherently malicious, can be manipulated to perform harmful actions based on its interaction with the application's environment.
• How it Works:
  • The attacker identifies an input field or parameter where the application accepts a class name.
  • The attacker crafts a malicious class name string.
  • The attacker submits the malicious input.
  • The application, lacking proper validation, passes the malicious class name to Instantiator::instantiate().
  • Instantiator instantiates the malicious class.
  • The malicious class's code (potentially in __wakeup if deserialization is involved) executes, compromising the application.
• Likelihood: High (if input is not properly validated)
• Impact: High to Very High (potential for arbitrary code execution)
• Effort: Low
• Skill Level: Novice to Intermediate
• Detection Difficulty: Medium
• Mitigation:
  • Strict Whitelisting: The application must validate the class name against a strict whitelist of allowed classes.
  • Input Sanitization: Sanitize the input to ensure it conforms to expected class name formats.
  • Principle of Least Privilege: Run the application with minimal privileges.

Attack Tree Path: 3. Exploit Deserialization Vulnerabilities [CRITICAL]

• Description: The attacker exploits a vulnerability in the application's deserialization process (e.g., using unserialize(), JSON deserialization, or other methods) to inject a malicious object. Even though Instantiator bypasses constructors, the __wakeup() method (or other magic methods) of the injected object can be used to execute arbitrary code. This is the most dangerous attack vector when Instantiator is used in conjunction with deserialization.
• How it Works:
  • The attacker identifies a point where the application deserializes data from an untrusted source.
  • The attacker crafts a malicious serialized payload containing an object of a class with a __wakeup() method (or other exploitable magic method).
  • The attacker sends the malicious payload to the application.
  • The application deserializes the payload.
  • Instantiator (potentially) is used to instantiate the deserialized object.
  • The __wakeup() method of the malicious object executes, leading to arbitrary code execution.
• Likelihood: High (if Instantiator is used with untrusted deserialized data)
• Impact: Very High (potential for arbitrary code execution)
• Effort: Low to Medium
• Skill Level: Intermediate to Advanced
• Detection Difficulty: Medium
• Mitigation:
  • Avoid Unsafe Deserialization: Never deserialize data from untrusted sources.
  • Use Secure Deserialization Libraries: If deserialization is necessary, use a secure library with whitelisting.
  • Input Validation (Before Deserialization): Validate input before deserialization.
  • Audit __wakeup() Methods: Carefully review any __wakeup() methods.

Attack Tree Path: 9. Supply Unexpected Arguments to __wakeup (if used) [CRITICAL]

• Description: This is a direct consequence of a successful deserialization attack (node 3). If a class has a __wakeup method, and the attacker controls the serialized data, they can control the data passed to __wakeup. This allows them to manipulate the behavior of __wakeup, potentially triggering vulnerabilities or unexpected code execution.
• How it Works:
  • This attack relies on the success of attack vector 3 (Exploit Deserialization Vulnerabilities).
  • The attacker crafts the serialized data to include specific values that will be passed to the __wakeup method.
  • When the object is deserialized and instantiated, the __wakeup method receives the attacker-controlled data.
  • The __wakeup method, potentially due to vulnerabilities or flawed logic, executes code based on the attacker-controlled data, leading to compromise.
• Likelihood: Medium (dependent on the presence and vulnerability of __wakeup methods)
• Impact: High to Very High (potential for arbitrary code execution or data corruption)
• Effort: Low to Medium
• Skill Level: Intermediate
• Detection Difficulty: Medium
• Mitigation:
  • Validate __wakeup Input: Carefully validate any data used within __wakeup methods.
  • Minimize __wakeup Logic: Keep __wakeup methods as simple as possible. Avoid complex logic.
  • All mitigations from attack vector 3 also apply here.