Provide references for CVE-2021-4388.
Where can I find more information about CVE-2021-4388?
References are available at: https://www.wordfence.com/threat-intel/vulnerabilities/id/5ce729a2-a106-45ab-b96c-cfe75246def7?source=cve, https://blog.nintechnet.com/multiple-wordpress-plugins-fixed-csrf-vulnerabilities-part-5/, https://plugins.trac.wordpress.org/browser/opal-estate/trunk/inc/ajax-functions.php#L177.