WP Post Popup <= 3.7.3 - Admin+ Stored XSS

Description The plugin does not sanitise and escape some of its inputs, 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

Enter the following payload in the Close Button field in the plugin settings. ![](s) Save the settings and visit the homepage to see the XSS.