Input validation vulnerability in MC4WP: Mailchimp for WordPress 4.9.16

The MC4WP plugin for WordPress, which helps integrate Mailchimp with WordPress websites, has a security issue where attackers can inject harmful code into a website through a specific field. This can happen if a certain placeholder, like {email}, is used in the field. The problem occurs in versions 4.9.9 to 4.9.15 due to a lack of proper safety measures. This means that anyone, even without proper authorization, can potentially add their own code to a website and cause harm if they can trick someone into clicking a link.