Provide references for CVE-2021-4389.
Where can I find more information about CVE-2021-4389?
References are available at: https://www.wordfence.com/threat-intel/vulnerabilities/id/28dea1e9-e772-488e-b98f-93a46ab84581?source=cve, https://blog.nintechnet.com/25-wordpress-plugins-vulnerable-to-csrf-attacks/, https://blog.nintechnet.com/more-wordpress-plugins-and-themes-vulnerable-to-csrf-attacks/, 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/multiple-wordpress-plugins-fixed-csrf-vulnerabilities-part-5/, https://blog.nintechnet.com/multiple-wordpress-plugins-fixed-csrf-vulnerabilities-part-4/, https://plugins.trac.wordpress.org/changeset/2477827/wp-travel/tags/4.4.7/inc/admin/class-admin-metaboxes.php.