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.

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.

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.

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.

admin/roles/override.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 gain privileges by leveraging the teacher role and modifying their own capabilities, as demonstrated by obtaining the backup:userinfo capability.

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.

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.

Cross-site scripting (XSS) vulnerability in blog/lib.php in the blog implementation in Moodle 1.9.x before 1.9.18, when Internet Explorer is used, allows remote attackers to inject arbitrary web script or HTML via a crafted parameter to blog/index.php.

SQL injection vulnerability in calendar/event.php in the calendar implementation in Moodle 1.9.x before 1.9.18 allows remote authenticated users to execute arbitrary SQL commands via a crafted calendar event.

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 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 idnumber field to cohort/edit.php.

mod/data/preset.php in Moodle 2.1.x before 2.1.6 and 2.2.x before 2.2.3 does not properly iterate through an array, which allows remote authenticated users to overwrite arbitrary database activity presets via unspecified vectors.

Moodle 1.9.x before 1.9.18, 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 the moodle/calendar:manageownentries capability requirement and add a calendar entry via a New Entry action.

Moodle 2.3.x before 2.3.1 uses only a client-side check for whether references are permitted in a file upload, which allows remote authenticated users to bypass intended alias (aka shortcut) restrictions via a client that omits this check.

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.

Multiple cross-site scripting (XSS) vulnerabilities in mod/lti/typessettings.php in Moodle 2.2.x before 2.2.4 and 2.3.x before 2.3.1 allow remote attackers to inject arbitrary web script or HTML via the (1) lti_typename or (2) lti_toolurl parameter.

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.

mod/forum/rsslib.php in Moodle 2.1.x before 2.1.7 and 2.2.x before 2.2.4 does not properly implement the requirement for posting before reading a Q&A forum, which allows remote authenticated users to bypass intended access restrictions by leveraging the student role and reading the RSS feed for a forum.

mod/forum/unsubscribeall.php in Moodle 2.1.x before 2.1.7 and 2.2.x before 2.2.4 does not consider whether a forum is optional, which allows remote authenticated users to bypass forum-subscription requirements by leveraging the student role and unsubscribing from all forums.