Serial Codes Generator and Validator with WooCommerce Support <= 2.8.2 - Missing Authorization

This research plan outlines the methodology for exploiting CVE-2025-62091, a missing authorization vulnerability in the "Serial Codes Generator and Validator with WooCommerce Support" plugin.

1. Vulnerability Summary

The plugin fails to implement proper capability checks (authorization) on one or more of its AJAX handlers. This allow an authenticated user with minimal privileges (Subscriber) to execute sensitive administrative functions, such as generating, deleting, or modifying serial codes or plugin settings. The vulnerability exists because the code relies solely on nonce verification (CSRF protection) without checking the user's roles or capabilities via current_user_can().

2. Attack Vector Analysis

• Endpoint: /wp-admin/admin-ajax.php
• Action (Inferred): Likely sc_delete_serial_code, sc_generate_serial_codes, or sc_save_settings.
• Authentication: Subscriber level (PR:L).
• Payload Parameter: action, security (nonce), and functional parameters (e.g., id, code_prefix).
• Preconditions: The attacker must be logged in as a Subscriber and obtain a valid nonce for the specific action.

3. Code Flow (Inferred)

1. Registration: The plugin registers AJAX actions using add_action( 'wp_ajax_...', ... ).
2. Handler Entry: When a request is sent to admin-ajax.php with the corresponding action, WordPress invokes the callback.
3. Verification (Incomplete): The callback likely calls check_ajax_referer( 'sc_nonce', 'security' ) or wp_verify_nonce(). This checks that the request is intentional (CSRF) but not that the user is authorized.
4. Missing Check: The callback omits a call to current_user_can( 'manage_options' ).
5. Execution: The function proceeds to perform a database operation (e.g., $wpdb->delete or $wpdb->insert) based on the user-provided parameters.

4. Nonce Acquisition Strategy

To bypass the CSRF protection, the agent must find where the nonce is localized.

1. Identify Action and Variable: Search the codebase for the registration of the AJAX action and the localization of the nonce.
   • grep -rn "wp_ajax_" .
   • grep -rn "wp_localize_script" .
2. Find Localization Key: Look for a key like sc_ajax or serial_codes_obj and a nonce field like security or nonce.
3. Check Script Enqueueing: Determine if the script (and thus the nonce) is loaded for all authenticated users in the admin area (e.g., on wp-admin/profile.php).
4. Extraction:
   • Login as a Subscriber.
   • Navigate to an admin page where scripts are likely loaded (e.g., /wp-admin/profile.php).
   • Use browser_eval to extract the nonce:
     browser_eval("window.sc_ajax_object?.nonce") (Replace with the actual variable discovered in Step 1).

5. Exploitation Strategy

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

1. Identify Target Action: For this PoC, we will target the deletion of a serial code (if an action like sc_delete_serial_code exists) or the generation of codes.
2. Prepare the Payload:
   • action: The vulnerable action string found in the code.
   • security: The extracted nonce.
   • id: The ID of a serial code to delete (if applicable).
3. Request: Use http_request to send a POST request.

Example Request (Template):

{
  "method": "POST",
  "url": "http://localhost:8080/wp-admin/admin-ajax.php",
  "headers": {
    "Content-Type": "application/x-www-form-urlencoded"
  },
  "body": "action=sc_delete_serial_code&security=NONCE_VALUE&id=1"
}

6. Test Data Setup

Before exploitation, the environment must contain data to be modified:

1. Log in as Admin.
2. Create Serial Codes: Use the plugin interface or WP-CLI to populate the wp_serial_codes (inferred table name) table.
   • wp eval "global \$wpdb; \$wpdb->insert(\$wpdb->prefix . 'serial_codes', ['code' => 'TEST-123', 'status' => 'available']);" (Verify table name first).
3. Create a Subscriber User:
   • wp user create attacker attacker@example.com --role=subscriber --user_pass=password

7. Expected Results

• Successful Exploit: The server returns a success response (e.g., 1, {"success":true}, or a redirect). The targeted serial code is deleted from the database or new codes are generated.
• Unauthorized (Fixed): The server returns a 403 Forbidden or a -1 error, indicating the nonce failed or the capability check (added in 2.8.3) blocked the request.

8. Verification Steps

After the http_request, verify the outcome using WP-CLI:

1. Check Database State:
   • wp db query "SELECT * FROM wp_serial_codes WHERE code='TEST-123';"
   • Confirm the row is missing (if testing deletion) or new rows exist (if testing generation).
2. Audit Logs: If the plugin has logging, check if the action was logged as being performed by the 'attacker' user.

9. Alternative Approaches

• Settings Modification: If sc_save_settings is vulnerable, attempt to change a sensitive setting like sc_allow_guest_validation or sc_prefix.
• Code Generation: Attempt to generate 10,000 serial codes to demonstrate impact on resource consumption (A:N).
• Direct Initialization: Check if the plugin processes requests via admin_init without checking DOING_AJAX. If so, the request might be simpler (GET request to /wp-admin/admin-post.php or similar).

Initial Discovery Commands for the Agent:

# 1. Find all AJAX handlers
grep -rn "wp_ajax_" .

# 2. Look for the specific handler callbacks
# Example: if action is 'sc_delete_code', find 'function sc_delete_code'
grep -rn "function " . | grep -i "serial"

# 3. Search for missing capability checks in those functions
# Look for handlers that use check_ajax_referer but DON'T use current_user_can
grep -rL "current_user_can" $(grep -rl "wp_ajax_" .)