Provide references for CVE-2021-39313.
Where can I find more information about CVE-2021-39313?
References are available at: https://www.wordfence.com/vulnerability-advisories/#CVE-2021-39313, https://plugins.trac.wordpress.org/browser/simple-responsive-image-gallery/tags/1.0.6/simple-image-gallery.php#L420.