Exploitation Research Plan: CVE-2026-25020 - WP Sync for Notion Missing Authorization

1. Vulnerability Summary

The WP Sync for Notion plugin (<= 1.7.0) is vulnerable to Missing Authorization. The plugin registers several AJAX handlers intended for administrative use (such as triggering synchronizations or modifying settings) but fails to implement a current_user_can() capability check within the callback functions. While these handlers are protected by WordPress nonces, the nonces are localized into the WordPress admin dashboard, making them accessible to any logged-in user, including those with the Contributor role. An attacker with Contributor-level access can leverage these nonces to perform unauthorized actions like triggering a Notion-to-WordPress sync.

2. Attack Vector Analysis

• Endpoint: /wp-admin/admin-ajax.php
• Action: wpsfn_run_sync (inferred action name for triggering a sync) or wpsfn_save_settings.
• Required Authentication: Authenticated user with Contributor role or higher.
• Parameters:
  • action: wpsfn_run_sync
  • nonce: A valid nonce for the wpsfn_nonce action.
  • id: The ID of the Notion connection/sync to trigger (inferred).
• Preconditions: At least one Notion sync connection must be configured by an administrator.

3. Code Flow (Inferred)

1. Registration: In includes/class-wp-sync-for-notion.php or admin/class-wp-sync-for-notion-admin.php, the plugin registers the AJAX hook:
   add_action( 'wp_ajax_wpsfn_run_sync', array( $this, 'run_sync' ) );
2. Entry Point: A Contributor user sends a POST request to admin-ajax.php with action=wpsfn_run_sync.
3. Nonce Verification: The handler run_sync() calls:
   check_ajax_referer( 'wpsfn_nonce', 'nonce' ); (Success, as the Contributor can obtain this nonce).
4. Missing Check: The handler fails to call current_user_can( 'manage_options' ).
5. Execution: The handler proceeds to initiate the sync process:
   $sync_manager = new WP_Sync_For_Notion_Sync_Manager( $_POST['id'] );
$sync_manager->run();

4. Nonce Acquisition Strategy

The plugin localizes the nonce for its administrative scripts. Since any user with the Contributor role can access the WordPress admin dashboard (/wp-admin/), they can extract the nonce from the global JavaScript objects initialized by the plugin.

1. Identify Script Localization: Search for wp_localize_script in the plugin's admin classes. It is likely localized under the handle wpsfn_admin or wpsfn_ajax.
2. Access Admin Dashboard: Navigate to /wp-admin/index.php as a Contributor.
3. Extract via Browser: Use browser_eval to retrieve the nonce.
   • Target Variable: window.wpsfn_admin?.nonce or window.wpsfn_ajax?.nonce (inferred).
   • Alternative: View the page source and look for var wpsfn_admin = {"nonce":"..."}.

5. Exploitation Strategy

1. Step 1: Setup Environment: Create a Notion sync connection (mock or real) as an admin. Identify its ID (usually an integer).
2. Step 2: Authenticate as Contributor: Log in to the target WordPress site with Contributor credentials.
3. Step 3: Extract Nonce:
   • Use browser_navigate to /wp-admin/.
   • Use browser_eval to get the nonce: browser_eval("wpsfn_admin.nonce").
4. Step 4: Trigger Unauthorized Action: Send a POST request to admin-ajax.php using the http_request tool.

Example Request:

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

action=wpsfn_run_sync&nonce=[EXTRACTED_NONCE]&id=1

6. Test Data Setup

1. Plugin Installation: Install wp-sync-for-notion version 1.7.0.
2. Admin Setup:
   • Create a dummy "Connection" in the plugin settings.
   • Note the id of this connection (check the URL in the admin panel or the database table wp_wpsfn_connections).
3. Attacker Setup:
   • Create a user with the username attacker and role contributor.

7. Expected Results

• Success: The server returns a 200 OK response, likely with a JSON body: {"success": true}.
• Side Effect: The plugin initiates a sync process. Depending on the configuration, this might create new posts or update existing ones, which should be restricted to administrators.
• Failure (Patched): The server returns a 403 Forbidden or 0 if the capability check is added.

8. Verification Steps

1. Check Sync Status: After the exploit, use WP-CLI to check the sync logs or last sync timestamp:
   wp option get wpsfn_last_sync_1 (inferred option name).
2. Verify Process: Check if new posts have been created or modified that correspond to the Notion connection ID used.
3. Check Capabilities: Attempt the same request without a nonce or with a subscriber-level account to see if the plugin handles unauthorized requests differently (though the vulnerability specifically mentions Contributor+).

9. Alternative Approaches

• Action Guessing: If wpsfn_run_sync is not the correct action name, grep the source code for add_action( 'wp_ajax_ to find all available administrative AJAX endpoints.
• Settings Modification: Check if wpsfn_save_settings or wpsfn_update_connection are also registered without authorization checks. These would be higher impact as they allow an attacker to redirect Notion syncs to their own Notion workspace.
• Parameter Variation: If id is not the correct parameter for the connection, check the run_sync function signature for $_POST or $_REQUEST keys.