Exploitation Research Plan: CVE-2026-7626 (Slek Gateway for WooCommerce)

1. Vulnerability Summary

The Slek Gateway for WooCommerce plugin (versions <= 1.0) suffers from a medium-severity Information Exposure vulnerability. The vulnerability resides in the wsb_handle_slek_payment_redirect() function. When a user proceeds to the payment stage of a WooCommerce order using the Slek gateway, the plugin generates an intermediate "redirect" page.

The flaw exists because the plugin directly embeds sensitive merchant API credentials—slek_key and slek_secret—into the HTML as hidden form fields. Furthermore, the slek_secret is appended as a plaintext GET parameter to the IPN (Instant Payment Notification) callback URL within that same page. An attacker (or even a malicious script on the client side) can extract these credentials by inspecting the page source before the JavaScript-based auto-submission of the payment form occurs.

2. Attack Vector Analysis

• Endpoint: WooCommerce "Order Pay" page or a custom redirect handler. (Likely /checkout/order-pay/[ORDER_ID]/?key=[ORDER_KEY]).
• Vulnerable Function: wsb_handle_slek_payment_redirect() (inferred to be triggered during the payment processing phase).
• Authentication: Unauthenticated (if guest checkout is enabled) or low-privileged "Customer" role.
• Preconditions:
  • The Slek Gateway must be enabled and configured with API credentials.
  • An order must be placed using Slek as the payment method.

3. Code Flow (Inferred)

1. Checkout Initiation: User selects "Slek" at checkout and clicks "Place Order".
2. Payment Processing: WooCommerce calls the gateway's process_payment($order_id) method.
3. Redirect Generation: The gateway returns a redirect URL to the "order-pay" page.
4. Template Execution: On the order-pay page, the plugin triggers wsb_handle_slek_payment_redirect().
5. Information Leak:
   • The function retrieves slek_key and slek_secret using get_option() or the gateway's settings.
   • It renders an HTML form destined for the Slek payment API.
   • It populates <input type="hidden" name="slek_key" value="..."> and <input type="hidden" name="slek_secret" value="...">.
   • It constructs a callback URL: https://site.com/?slek_callback=1&secret=[SLEK_SECRET].
6. Client Exposure: The HTML is sent to the browser. While JavaScript typically submits this form immediately, the raw HTTP response contains the secrets.

4. Nonce Acquisition Strategy

This vulnerability does not require a WordPress nonce to trigger the exposure, as the exposure occurs during the standard WooCommerce checkout flow which is designed for public access. However, to reach the vulnerable page, a valid WooCommerce order must be created.

Strategy to reach the exposure point:

1. Identify Checkout Nonce: WooCommerce requires a woocommerce-process-checkout-nonce to place an order via AJAX/POST.
2. Navigate to Checkout: Use browser_navigate to /checkout/.
3. Extract Nonce: Use browser_eval to extract the checkout nonce:
   browser_eval("document.getElementById('woocommerce-process-checkout-nonce')?.value").
4. Place Order: Submit the checkout form or use http_request to POST to /?wc-ajax=checkout.

5. Exploitation Strategy

1. Setup Phase:
   • Configure the Slek Gateway with placeholder credentials (e.g., TEST_KEY_12345 and TEST_SECRET_67890).
   • Ensure a product exists in the WooCommerce store.
2. Order Phase:
   • Add a product to the cart.
   • Navigate to the checkout page.
   • Select "Slek" as the payment method.
   • Place the order. This will yield an "Order Pay" URL or a redirect to the Slek handler.
3. Capture Phase:
   • Navigate to the resulting order-pay URL using the browser_navigate tool.
   • Crucial Step: Since the page auto-submits, use browser_get_source immediately upon load, or ideally, intercept the network request.
   • Search the HTML source for:
     • type="hidden" inputs with names related to slek_key or slek_secret.
     • URL strings containing the callback/IPN parameters.
4. Extraction: Extract the plaintext credentials from the value attributes and the URL parameter.

6. Test Data Setup

• Plugin Configuration:

  # Enable Slek Gateway (slug inferred)
  wp option update woocommerce_slek_settings '{"enabled":"yes","slek_key":"EXPOSED_KEY_VAL","slek_secret":"EXPOSED_SECRET_VAL"}' --format=json
  

• Product Creation: Ensure at least one publishable product exists.
• Settings: Enable "Guest Checkout" in WooCommerce settings to simplify the attack (Account & Privacy -> Guest checkout).

7. Expected Results

• The HTTP response for the redirect page will contain:
  • <input type="hidden" name="slek_key" value="EXPOSED_KEY_VAL">
  • <input type="hidden" name="slek_secret" value="EXPOSED_SECRET_VAL">
  • A URL string resembling ...&slek_secret=EXPOSED_SECRET_VAL... or ...&secret=EXPOSED_SECRET_VAL....
• A successful exploit confirms that an unauthenticated user can retrieve the merchant's private API keys simply by placing a dummy order.

8. Verification Steps

1. Compare Credentials: Use WP-CLI to verify the leaked credentials match the database:

   wp option get woocommerce_slek_settings
   

2. Check IPN URL: Verify the IPN URL in the source contains the same secret found in the form fields.

9. Alternative Approaches

• Proxy/Intercept: If the browser auto-submits too quickly for browser_get_source, use the http_request tool to manually request the order-pay URL (which is a GET request). This allows reading the response body without executing the JavaScript that triggers the redirect.
• Search for wsb_handle_slek_payment_redirect: If the primary WooCommerce redirect path is modified, search the codebase for where wsb_handle_slek_payment_redirect is hooked (e.g., template_redirect, init, or a WooCommerce-specific hook like woocommerce_receipt_slek).