Multiple cross-site scripting (XSS) vulnerabilities in phpBB 2.0.17 and earlier allow remote attackers to inject arbitrary web script or HTML via the (1) error_msg parameter to usercp_register.php, (2) forward_page parameter to login.php, and (3) list_cat parameter to search.php, which are not initialized as variables.
http://www.vupen.com/english/advisories/2005/2250
http://www.securityfocus.com/bid/15243
http://www.hardened-php.net/advisory_172005.75.html
http://www.debian.org/security/2005/dsa-925
http://securitytracker.com/id?1015121
http://securityreason.com/securityalert/130
http://secunia.com/advisories/18098