Cross-site scripting (XSS) vulnerability in sign.php in tinyguestbook allows remote attackers to inject arbitrary web script or HTML via the msg parameter.
https://exchange.xforce.ibmcloud.com/vulnerabilities/72075
http://www.securityfocus.com/bid/51248
http://secunia.com/advisories/47419
http://archives.neohapsis.com/archives/bugtraq/2012-01/0009.html