Moodle 2.0.x before 2.0.5 and 2.1.x before 2.1.2 allows remote attackers to bypass intended access restrictions and perform global searches by leveraging the guest role and making a direct request to a URL.
https://bugzilla.redhat.com/show_bug.cgi?id=747444
http://moodle.org/mod/forum/discuss.php?d=188323
http://git.moodle.org/gw?p=moodle.git%3Ba=commit%3Bh=5eb1cec34f013fdcb559b66bc401f2845ce0bbb7