A flaw was found in Moodle before versions 3.7, 3.6.4. A web service fetching messages was not restricted to the current user's conversations.
lib/moodlelib.php in Moodle through 2.6.11, 2.7.x before 2.7.10, 2.8.x before 2.8.8, and 2.9.x before 2.9.2 relies on the PHP mt_rand function to implement the random_string and complex_random_string functions, which makes it easier for remote attackers to predict password-recovery tokens via a brute-force approach.
In Moodle 2.x and 3.x, the capability to view course notes is checked in the wrong context.
In Moodle 2.x and 3.x, the question engine allows access to files that should not be available.