Keap Official Opt-in Forms <= 1.0.11 - 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. Store the script in non-sanitized fields like ‘Opt in title’, ‘Opt in message’, and ‘Success Message text’: 2. Visit the website, and then the script gets executed.