chatbox.php in e107 0.554 and 0.603 allows remote attackers to cause a denial of service (pages fail to load) via HTML in the Name field, which prevents the main.php form from being loaded.
https://exchange.xforce.ibmcloud.com/vulnerabilities/13553
http://www.hackingheaven.com/index.php?name=PNphpBB2&file=viewtopic&t=21