Easy!Appointments is a self hosted appointment scheduler. In 1.5.2 and earlier, application/core/EA_Security.php::csrf_verify() only enforces CSRF for POST requests and returns early for non-POST methods. Several application endpoints perform state-changing operations while accepting parameters from GET (or $_REQUEST), so an attacker can perform CSRF by forcing a victim's browser to issue a crafted GET request. Impact: creation of admin accounts, modification of admin email/password, and full admin account takeover.
Cross-Site Request Forgery (CSRF) vulnerability in alextselegidis Easy!Appointments allows Cross Site Request Forgery. This issue affects Easy!Appointments: from n/a through 1.4.2.
The Easy!Appointments plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the plugin's shortcode(s) in all versions up to, and including, 1.3.1 due to insufficient input sanitization and output escaping on user supplied attributes. This makes it possible for authenticated attackers with contributor-level and above permissions to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.