Exploitation Research Plan - CVE-2025-67577 (Easy Form Builder)

1. Vulnerability Summary

The Easy Form Builder plugin for WordPress is vulnerable to Missing Authorization in versions up to 3.8.20. This vulnerability occurs because several administrative functions are registered via wp_ajax_nopriv_ hooks or registered via wp_ajax_ without accompanying current_user_can() capability checks. This allows an unauthenticated attacker to perform actions that should be restricted to administrators, such as modifying form configurations, toggling form statuses, or accessing internal plugin data.

2. Attack Vector Analysis

• Endpoint: /wp-admin/admin-ajax.php
• Action: efb_update_form_status (inferred) or efb_save_form_settings (inferred).
• Authentication: None required (unauthenticated).
• Preconditions: At least one form must exist in the plugin for the attacker to manipulate.
• Vulnerable Parameter: form_id (the target form), status (the new status to set), and nonce.

3. Code Flow

1. Registration: The plugin registers AJAX handlers in includes/class-easy-form-builder-ajax.php (inferred) or the main plugin file using add_action( 'wp_ajax_nopriv_efb_update_form_status', '...' ).
2. Entry Point: An unauthenticated request is sent to admin-ajax.php with action=efb_update_form_status.
3. Missing Check: The callback function associated with the action performs a check_ajax_referer (to prevent CSRF) but fails to call current_user_can( 'manage_options' ).
4. Sink: The function proceeds to update the wp_posts table or the plugin's custom table (e.g., wp_efb_forms) to change the status/configuration of a form based on the user-provided form_id.

4. Nonce Acquisition Strategy

The plugin exposes nonces to the frontend to facilitate AJAX submissions. These nonces are often valid for administrative AJAX actions if the plugin uses a generic nonce.

1. Shortcode: The plugin uses [efb_form id="ID"] to render forms.
2. Execution:
   • Create a test page containing any Easy Form Builder form: wp post create --post_type=page --post_status=publish --post_content='[efb_form id="1"]'
   • Navigate to the page.
   • Use browser_eval to extract the nonce from the localized JavaScript object.
3. JS Variable: window.easy_form_builder_php?.ajax_nonce (inferred) or window.efb_var?.nonce (inferred).

5. Exploitation Strategy

The goal is to toggle the status of an existing form (e.g., deactivating a lead capture form).

Step 1: Discover Form ID
Unauthenticated users can often see form IDs in the HTML source code of pages where the form is embedded (look for id="efb-form-..." or shortcode attributes).

Step 2: Obtain Nonce
Use the browser to extract the nonce from the easy_form_builder_php object.

Step 3: Unauthorized Status Change Request
Send a POST request to admin-ajax.php.

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

  action=efb_update_form_status&form_id=1&status=inactive&nonce=[EXTRACTED_NONCE]
  

6. Test Data Setup

1. Plugin Installation: Ensure easy-form-builder version 3.8.20 is installed.
2. Create Form:
   • Use WP-CLI to create a dummy form if possible, or use browser_navigate to create one manually in the admin UI as an admin user.
3. Publish Form: Place the form on a public page:
   • wp post create --post_type=page --post_title="Contact" --post_status=publish --post_content='[efb_form id="1"]'

7. Expected Results

• Response: The server should return a JSON success message (e.g., {"success":true}) or a 1.
• Impact: The form with ID 1 will no longer appear on the frontend or will be marked as "Inactive" in the admin dashboard.

8. Verification Steps

1. Database Check:
   • Use WP-CLI to check the status of the form in the database:
     wp db query "SELECT status FROM wp_efb_forms WHERE id=1;" (Note: Table name is inferred).
2. Frontend Check:
   • Navigate to the page where the form was embedded. Confirm the form is no longer rendering or displays an "inactive" message.
3. Admin UI Check:
   • Log in as admin and verify the form status in the Easy Form Builder menu.

9. Alternative Approaches

If efb_update_form_status is not the correct action name:

• Grep for AJAX actions: Run grep -r "wp_ajax_nopriv_" wp-content/plugins/easy-form-builder/ to find all unauthenticated entry points.
• Analyze efb_add_submission: Check if the submission handler itself can be used to overwrite form settings by passing unexpected parameters (Mass Assignment).
• Check for efb_export_data: If the vulnerability allows data exposure, attempt to call an export action without a capability check to download form entries.