Multiple open redirect vulnerabilities in Moodle 2.2.x before 2.2.7, 2.3.x before 2.3.4, and 2.4.x before 2.4.1 allow remote attackers to redirect users to arbitrary web sites and conduct phishing attacks via vectors related to (1) backup/backupfilesedit.php, (2) comment/comment_post.php, (3) course/switchrole.php, (4) mod/wiki/filesedit.php, (5) tag/coursetags_add.php, or (6) user/files.php.