The rc4encrypt function in lib/moodlelib.php in Moodle 1.9.x before 1.9.16, 2.0.x before 2.0.7, 2.1.x before 2.1.4, and 2.2.x before 2.2.1 uses a hardcoded password of nfgjeingjk, which makes it easier for remote attackers to defeat cryptographic protection mechanisms by reading this script's source code within the open-source software distribution.

Moodle 1.9.x before 1.9.16, 2.0.x before 2.0.7, 2.1.x before 2.1.4, and 2.2.x before 2.2.1 allows remote attackers to view the profile images of arbitrary user accounts via unspecified vectors.

Moodle 1.9.x before 1.9.16, 2.0.x before 2.0.7, 2.1.x before 2.1.4, and 2.2.x before 2.2.1 does not validate e-mail address settings, which allows remote authenticated users to have an unspecified impact via a crafted address.

mod/forum/user.php in Moodle 1.9.x before 1.9.16 allows remote authenticated users to obtain the names and other details of arbitrary user accounts by searching for posts.

mod/forum/user.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 allows remote authenticated users to discover the names of other users via unspecified vectors.

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.

message/refresh.php in Moodle 1.9.x before 1.9.14 allows remote authenticated users to cause a denial of service (infinite request loop) via a URL that specifies a zero wait time for message refreshing.

Cross-site scripting (XSS) vulnerability in course/editsection.html in Moodle 1.9.x before 1.9.14 allows remote authenticated users to inject arbitrary web script or HTML via crafted data.

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.