auth/ldap/ntlmsso_attempt.php in Moodle 2.0.x before 2.0.10, 2.1.x before 2.1.7, 2.2.x before 2.2.4, and 2.3.x before 2.3.1 redirects users from an https LDAP login URL to an http URL, which allows remote attackers to obtain sensitive information by sniffing the network.

The is_enrolled function in lib/accesslib.php in Moodle 2.2.x before 2.2.4 and 2.3.x before 2.3.1 does not properly interact with the caching feature, which might allow remote authenticated users to bypass an intended capability check via unspecified vectors that trigger caching of a user record.

lib/filelib.php in Moodle 2.1.x before 2.1.7 and 2.2.x before 2.2.4 does not properly restrict file access after a block has been hidden, which allows remote authenticated users to obtain sensitive information by reading a file that is embedded in a block.

Cross-site scripting (XSS) vulnerability in lib/filelib.php in 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 inject arbitrary web script or HTML via an assignment submission with zip compression, leading to text/html rendering during a "download all" action.

Cross-site scripting (XSS) vulnerability in admin/webservice/forms.php in the web services implementation in 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 inject arbitrary web script or HTML via the name field (aka the service name) to admin/webservice/service.php.

Moodle 2.1.x before 2.1.6 and 2.2.x before 2.2.3 allows remote authenticated users to bypass the moodle/site:readallmessages capability requirement and read arbitrary messages by using the "Recent conversations" feature with a modified parameter in a URL.

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.

The question-bank functionality in Moodle 2.1.x before 2.1.6 and 2.2.x before 2.2.3 allows remote authenticated users to bypass intended capability requirements and save questions via a save_question action.

Moodle 2.1.x before 2.1.6 and 2.2.x before 2.2.3 allows remote authenticated users to bypass question:use* capability requirements and add arbitrary questions to a quiz via the questions feature.

Cross-site scripting (XSS) vulnerability in the Wiki subsystem in 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 inject arbitrary web script or HTML via a crafted string that is inserted into a page title.