lib/moodlelib.php in Moodle through 2.5.9, 2.6.x before 2.6.9, 2.7.x before 2.7.6, and 2.8.x before 2.8.4, when the theme uses the blocks-regions feature, establishes the course state at an incorrect point in the login-validation process, which allows remote attackers to obtain sensitive course information via unspecified vectors.