The MoodleQuickForm class in the Forms Library in lib/formslib.php in Moodle 1.9.x before 1.9.14, 2.0.x before 2.0.5, and 2.1.x before 2.1.2 does not recognize Forms API setConstant operations, which allows remote attackers to submit unexpected form content by modifying the values of constant fields.

The chat functionality in Moodle 2.0.x before 2.0.5 and 2.1.x before 2.1.2 allows remote authenticated users to discover the name of any user via a beep operation.

mnet/xmlrpc/client.php in MNET in Moodle 1.9.x before 1.9.14, 2.0.x before 2.0.5, and 2.1.x before 2.1.2 does not properly process the return value of the openssl_verify function, which allows remote attackers to bypass validation via a crafted certificate.

CRLF injection vulnerability in calendar/set.php in the Calendar component in Moodle 1.9.x before 1.9.15, 2.0.x before 2.0.6, 2.1.x before 2.1.3, and 2.2 allows remote attackers to inject arbitrary HTTP headers and conduct HTTP response splitting attacks via vectors involving the url variable.