Easy Form Builder < 3.8.9 - Missing Authorization to Authenticated (Subscriber+) Stored Cross-Site Scripting

Description

The Easy Form Builder – WordPress plugin form builder: contact form, survey form, payment form, and custom form builder plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'name' parameter of the 'add_form_Emsfb' AJAX action in all versions up to, and including, 3.8.8 due to insufficient input sanitization and output escaping and missing authorization checks. This makes it possible for authenticated attackers, with Subscriber-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.