An issue was discovered in custom/ajax_download.php in OpenEMR before 5.0.2 via the fileName parameter. An attacker can download any file (that is readable by the user www-data) from server storage. If the requested file is writable for the www-data user and the directory /var/www/openemr/sites/default/documents/cqm_qrda/ exists, it will be deleted from server.