Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in Nikola Loncar Easy Appointments allows Stored XSS.This issue affects Easy Appointments: from n/a through 3.10.7.

Cross-Site Request Forgery (CSRF) vulnerability in Nikola Loncar Easy Appointments plugin <= 3.11.9 versions.

The Easy Appointments plugin for WordPress is vulnerable to unauthorized modification of data due to insufficient user validation on the ajaxcancelappointment() function in all versions up to, and including, 3.11.18. This makes it possible for unauthenticated attackers to cancel other users orders.

The Easy Appointments plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the plugin's 'eafullcalendar' shortcode in all versions up to, and including, 3.11.18 due to insufficient input sanitization and output escaping on user supplied attributes. This makes it possible for authenticated attackers, with contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.

The Easy Appointments WordPress plugin before 3.11.2 does not validate and escape some of its shortcode attributes before outputting them back in the page, which could allow users with a role as low as contributor to perform Stored Cross-Site Scripting attacks which could be used against high privilege users such as admins.

The Easy Appointments plugin before 1.12.0 for WordPress has XSS via a Settings values in the admin panel.