Cross-site scripting (XSS) vulnerability in the phpCAS client library before 1.1.0, as used in Moodle 1.8.x before 1.8.12 and 1.9.x before 1.9.8, allows remote attackers to inject arbitrary web script or HTML via a crafted URL, which is not properly handled in an error message.
http://www.vupen.com/english/advisories/2010/1107
http://www.ja-sig.org/wiki/display/CASC/phpCAS+ChangeLog
http://www.ja-sig.org/issues/browse/PHPCAS-52
http://lists.opensuse.org/opensuse-security-announce/2010-05/msg00001.html