Provide references for CVE-2021-4420.
Where can I find more information about CVE-2021-4420?
References are available at: https://www.wordfence.com/threat-intel/vulnerabilities/id/da4592b6-5e84-4a89-9ade-6cc227740d32?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?sfp_email=&sfph_mail=&reponame=&old=2603629%40sell-media&new=2603629%40sell-media&sfp_email=&sfph_mail=.