Multiple cross-site scripting (XSS) vulnerabilities in pblguestbook.php in PBL Guestbook 1.31 allow remote attackers to inject arbitrary web script or HTML via javascript in the SRC attribute of IMG tags in the (1) name, (2) email, and (3) website parameter, which bypasses XSS protection mechanisms that check for SCRIPT tags but not IMG.  NOTE: portions of this description's details are obtained from third party information.