WP Subtitle < 3.4.1 - Contributor+ Stored Cross-Site Scripting

2022-04-2500:00:00

Francesco Carlucci

wordpress

subtitle

plugin

xss

stored

contributor+

EPSS

0.001

Percentile

24.8%

JSON

The plugin adds a subtitle field and provides a shortcode to display it via [wp_subtitle]. The subtitle is stored as a custom post meta with the key: “wps_subtitle”, which is sanitized upon post save/update, however is not sanitized when updating it directly from the post meta update button (via AJAX) - and this makes the XSS exploitable by authenticated users with a role as low as contributor.

- Create a post as contributor+ with the following shortcode in it [wp_subtitle], save the post
- Add a custom field named "wps_subtitle” with the following payload as value: <script>alert(/XSS/)</script> and save it **without** updating the post (from the custom fields meta box)
- View/preview the post/page to trigger the XSS

EPSS

0.001

Percentile

24.8%

JSON

Related for WPEX-ID:3491B889-94DD-4507-9FED-58F48D8275CF