* **Description:** An attacker manipulates the class name provided to the Instantiator, causing the application to create an object of an attacker-controlled class. This bypasses the intended constructor and any security checks it might contain.
* **How Instantiator Contributes:** The Instantiator's core function is to create objects *without* calling the constructor, making this attack possible. It directly facilitates the bypass of constructor-based security.
* **Example:**
* Application code: `$object = $instantiator->instantiate($_GET['class_name']);`
* Attacker provides: `?class_name=My\Evil\Class` (where `My\Evil\Class` has a `__wakeup` method that executes malicious code).
* **Impact:**
* Remote Code Execution (RCE)
* Denial of Service (DoS)
* Information Disclosure
* Privilege Escalation
* **Risk Severity:** Critical
* **Mitigation Strategies:**
* **Strict Whitelisting:** Maintain a hardcoded list of *only* the allowed class names. Do *not* derive the class name from user input, even indirectly. Use a configuration file or a mapping (e.g., a PHP array) to define the allowed classes.
* **Factory Pattern with Validation:** Use a factory method that takes a validated identifier (e.g., an enum or a key from a configuration array) and maps it to the corresponding class name *before* using the Instantiator. The factory method can then perform additional post-instantiation setup and validation.
* **Avoid User Input:** Never directly use user-supplied data to determine the class name to be instantiated.
* **Description:** The Instantiator bypasses the constructor of the target class. Constructors often contain essential security logic, such as access control checks, input validation, and initialization of security-related properties.
* **How Instantiator Contributes:** This is the fundamental mechanism of the Instantiator – to avoid calling the constructor. This bypass is the *intended* behavior, but it's also the source of the risk.
* **Example:**
```php
class User {
private $isAdmin;
public function __construct($username, $password) {
// Authentication and authorization logic here
if ($this->authenticate($username, $password)) {
$this->isAdmin = $this->checkAdminStatus($username);
} else {
$this->isAdmin = false;
}
}
// ... other methods ...
}
// Using Instantiator:
$user = $instantiator->instantiate(User::class);
// $user->isAdmin is now uninitialized (or has a default value, if any),
// bypassing the authentication and authorization logic.
```
* **Impact:**
* Privilege Escalation (if the constructor enforces access control)
* Data Corruption (if the constructor validates input)
* Security Bypass (general weakening of security posture)
* **Risk Severity:** High
* **Mitigation Strategies:**
* **Post-Instantiation Initialization:** Create a separate initialization method (e.g., `initialize()`, `setup()`, `validate()`) that performs the essential security checks and setup that would normally be in the constructor. Call this method *immediately* after using the Instantiator.
* **Factory Pattern:** Encapsulate the Instantiator usage within a factory method. The factory method instantiates the object, then calls the initialization method, ensuring that the object is always in a secure and consistent state.
* **Object State Validation:** Implement a method (e.g., `isValid()`) that checks the internal state of the object to ensure that all security-critical properties are properly initialized and that the object is in a valid state. Call this method before using the object.