The wp-mpdf plugin for WordPress is vulnerable to Cross-Site Request Forgery in versions up to, and including, 3.5.1. This is due to missing or incorrect nonce validation on the mpdf_admin_savepost() function. This makes it possible for unauthenticated attackers to save post data via a forged request granted they can trick a site administrator into performing an action such as clicking on a link.
https://plugins.trac.wordpress.org/changeset/2549363/wp-mpdf/trunk/wp-mpdf.php
https://blog.nintechnet.com/multiple-wordpress-plugins-fixed-csrf-vulnerabilities-part-5/
https://blog.nintechnet.com/multiple-wordpress-plugins-fixed-csrf-vulnerabilities-part-4/
https://blog.nintechnet.com/multiple-wordpress-plugins-fixed-csrf-vulnerabilities-part-3/
https://blog.nintechnet.com/multiple-wordpress-plugins-fixed-csrf-vulnerabilities-part-2/
https://blog.nintechnet.com/multiple-wordpress-plugins-fixed-csrf-vulnerabilities-part-1/
https://blog.nintechnet.com/more-wordpress-plugins-and-themes-vulnerable-to-csrf-attacks/
https://blog.nintechnet.com/25-wordpress-plugins-vulnerable-to-csrf-attacks/