Alemha Watermarker <= 1.3.1 - Author+ 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. As an “author” level user, add a new watermark: https://example.com/wp-admin/post-new.php?post_type=watermark 2. For the field “watermark text” field, enter the payload: "> 3. Save and see the XSS