Cross-site scripting (XSS) vulnerability in index.php in DT Guestbook (dt_guestbook) 1.0f, when register_globals is enabled, allows remote attackers to inject arbitrary web script or HTML via the error[] parameter.
https://exchange.xforce.ibmcloud.com/vulnerabilities/31518
http://www.vupen.com/english/advisories/2007/0205
http://www.securityfocus.com/bid/22078
http://www.securityfocus.com/archive/1/457059/100/0/threaded