Input validation vulnerability in Event Easy Calendar 1.0

The Event Easy Calendar plugin for WordPress has a security vulnerability in versions up to, and including, 1.0.0. This is because some of the functions do not have the correct security measures in place. This means that an attacker who is not logged in could get an administrator to do something, such as click a link, and this could then cause them to do things like create or update customers, create services and coupons, change settings, enable reminders and auto approvals, delete bookings, change the PayPal recipient email address, or change the cost of services.