CSSable Countdown <= 1.5 - Admin+ Stored XSS

Description The plugin does not sanitise and escape some of its settings, which could allow high privilege users such as admin to perform Stored Cross-Site Scripting attacks even when the unfiltered_html capability is disallowed (for example in multisite setup)

PoC

1. Go to https://example.com/wp-admin/widgets.php 2. Add the “CSSable Countdown” widget 3. Under “Add Text” add the payload `alert(1)