Research Plan: CVE-2025-69327 - Car Rental Manager Missing Authorization

1. Vulnerability Summary

The Car Rental Manager plugin (<= 1.0.9) suffers from a Missing Authorization vulnerability. Several AJAX handlers registered via wp_ajax_* hooks do not perform capability checks (e.g., current_user_can( 'manage_options' )). This allows any authenticated user, including those with Subscriber roles, to execute administrative functions such as modifying plugin settings, deleting data, or updating vehicle information.

2. Attack Vector Analysis

• Endpoint: /wp-admin/admin-ajax.php
• Action: To be determined via discovery, but likely car_rental_save_settings, crm_delete_vehicle, or crm_update_booking_status (inferred).
• Parameter: action (required), plus payload parameters and potentially a nonce.
• Authentication: Authenticated user with Subscriber role or higher.
• Preconditions: The plugin must be active. A nonce may be required, which is typically exposed in the WordPress admin dashboard or specific plugin pages.

3. Code Flow

1. Registration: The plugin registers AJAX actions in its main class or an admin-specific class (e.g., includes/class-car-rental-manager.php or admin/class-car-rental-manager-admin.php).
   • Code Pattern: add_action( 'wp_ajax_crm_save_settings', array( $this, 'save_settings' ) );
2. Trigger: An authenticated user sends a POST request to admin-ajax.php with action=crm_save_settings.
3. Vulnerable Callback: The function save_settings is executed.
4. The Flaw: The callback may verify a nonce using check_ajax_referer() but fails to call current_user_can() before performing sensitive operations (like update_option or $wpdb->delete).

4. Nonce Acquisition Strategy

The plugin likely localizes a nonce for its AJAX operations. Because this is a wp_ajax_ (authenticated) vulnerability, the nonce will be available to any logged-in user who can access the dashboard or a page where the plugin scripts are loaded.

1. Identify Localized Variable: Search the codebase for wp_localize_script.
   • Search: grep -r "wp_localize_script" .
2. Target Handle: Look for a handle like crm-admin-js or car-rental-manager.
3. Variable Name: Often something like crm_ajax_object or crm_params.
4. Extraction Path:
   • Create a Subscriber user and log in.
   • Navigate to the WordPress Dashboard (/wp-admin/index.php).
   • Use browser_eval to extract the nonce:

     // Example (verify variable name in source)
     window.crm_ajax_object?.nonce || window.crm_params?.nonce
     

5. Exploitation Strategy

Step 1: Discovery

Use grep to find all wp_ajax_ hooks and check their callbacks for authorization checks.

grep -rn "add_action.*wp_ajax_" .

For each found callback, check if current_user_can is present.

Step 2: Nonce Extraction

Log in as a Subscriber and extract the nonce from the dashboard.

Step 3: Unauthorized Request

Send a POST request to change a sensitive setting (e.g., the default booking status or an email recipient).

• URL: http://localhost:8080/wp-admin/admin-ajax.php
• Method: POST
• Headers: Content-Type: application/x-www-form-urlencoded
• Payload:

  action=crm_save_settings&nonce=[NONCE]&crm_option_name=admin_email&crm_option_value=attacker@example.com
  

  (Note: Parameter names are inferred and must be confirmed via grep of the callback function body).

6. Test Data Setup

1. Install Plugin: Ensure Car Rental Manager version 1.0.9 is installed.
2. Create User:

   wp user create attacker attacker@example.com --role=subscriber --user_pass=password
   

3. Initial State: Check current plugin settings.

   wp option get crm_settings (inferred)
   

7. Expected Results

• HTTP Response: 200 OK or a JSON success message (e.g., {"success":true}).
• Impact: The targeted setting or database record is modified despite the request originating from a Subscriber.

8. Verification Steps

1. Check Database: Use WP-CLI to verify the change.

   wp option get crm_settings
   

2. Check Management: If the exploit targeted vehicle deletion:

   wp post list --post_type=crm_vehicle (inferred)
   

9. Alternative Approaches

If the plugin does not load its scripts for Subscribers in the dashboard:

1. Check if any plugin shortcodes (e.g., [car_rental_system]) are available.
2. Create a public page with that shortcode.
3. Navigate to that page as the Subscriber to extract the nonce.
4. If no nonce is used in the wp_verify_nonce or check_ajax_referer call (i.e., the parameter is missing or the check is skipped), proceed with the POST request omitting the nonce.