The More From Google WordPress plugin is vulnerable to Reflected Cross-Site Scripting due to a reflected $_SERVER["PHP_SELF"] value in the ~/morefromgoogle.php file which allows attackers to inject arbitrary web scripts, in versions up to and including 0.0.2.
https://www.wordfence.com/vulnerability-advisories/#CVE-2021-38319
https://plugins.trac.wordpress.org/browser/more-from-google/trunk/morefromgoogle.php#L397