Multiple cross-site scripting (XSS) vulnerabilities in Moodle 1.8.x before 1.8.12 and 1.9.x before 1.9.8 allow remote attackers to inject arbitrary web script or HTML via vectors related to (1) the Login-As feature or (2) when the global search feature is enabled, unspecified global search forms in the Global Search Engine.  NOTE: vector 1 might be resultant from a cross-site request forgery (CSRF) vulnerability.