The Multi-Authentication feature in the Central Authentication Service (CAS) functionality in auth/cas/cas_form.html in Moodle 2.1.x before 2.1.6 and 2.2.x before 2.2.3 does not use HTTPS, which allows remote attackers to obtain credentials by sniffing the network.
Moodle 2.0.x before 2.0.9, 2.1.x before 2.1.6, and 2.2.x before 2.2.3 allows remote authenticated users to bypass an activity's read-only state and modify the database by leveraging the student role and editing database activity entries that already exist.
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.
class.phpmailer.php in the PHPMailer library, as used 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 and other products, allows remote authenticated users to inject arbitrary e-mail headers via vectors involving a crafted (1) From: or (2) Sender: header.
The webservices functionality in Moodle 2.0.x before 2.0.7, 2.1.x before 2.1.4, and 2.2.x before 2.2.1 allows remote authenticated users to bypass the deleted status and continue using a server via a token.
The self-enrolment functionality in Moodle 2.1.x before 2.1.4 and 2.2.x before 2.2.1 allows remote authenticated users to obtain the manager role by leveraging the teacher role.
The form-autocompletion functionality in Moodle 2.0.x before 2.0.7, 2.1.x before 2.1.4, and 2.2.x before 2.2.1 makes it easier for physically proximate attackers to discover passwords by reading the contents of a non-password field, as demonstrated by accessing a create-groups page with Safari on an iPad device.
lib/formslib.php in Moodle 2.1.x before 2.1.4 and 2.2.x before 2.2.1 does not properly handle multiple instances of a form element, which has unspecified impact and remote attack 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 allows remote attackers to view the profile images of arbitrary user accounts via unspecified vectors.
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.