Describe CVE-2021-39412.
What is CVE-2021-39412?
Multiple Cross Site Scripting (XSS) vulnerabilities exists in PHPGurukul Shopping v3.1 via the (1) callback parameter in (a) server_side/scripts/id_jsonp.php, (b) server_side/scripts/jsonp.php, and (c) scripts/objects_jsonp.php, the (2) value parameter in examples_support/editable_ajax.php, and the (3) PHP_SELF parameter in captcha/index.php..