A flaw was found in Moodle 3.4 to 3.4.1, and 3.3 to 3.3.4. If a user account using OAuth2 authentication method was once confirmed but later suspended, the user could still login to the site.

A flaw was found in Moodle 3.4 to 3.4.1, 3.3 to 3.3.4, 3.2 to 3.2.7, 3.1 to 3.1.10 and earlier unsupported versions. Unauthenticated users can trigger custom messages to admin via paypal enrol script. Paypal IPN callback script should only send error emails to admin after request origin was verified, otherwise admin email can be spammed.

In Moodle 3.x, there is XSS via a calendar event name.

In Moodle 3.x, quiz web services allow students to see quiz results when it is prohibited in the settings.

In Moodle 3.x, the setting for blocked hosts list can be bypassed with multiple A record hostnames.

Moodle 3.x has Server Side Request Forgery in the filepicker.

In Moodle 3.x, students can find out email addresses of other students in the same course. Using search on the Participants page, students could search email addresses of all participants regardless of email visibility. This allows enumerating and guessing emails of other students.

In Moodle 3.x, various course reports allow teachers to view details about users in the groups they can't access.

Moodle 3.x has XSS in the contact form on the "non-respondents" page in non-anonymous feedback.

In Moodle 3.x, course creators are able to change system default settings for courses.

Moodle 3.x has user fullname disclosure on the user preferences page.

Cross-site scripting (XSS) vulnerability in the Flash component infrastructure in YUI 2.5.0 through 2.8.1, as used in Bugzilla, Moodle, and other products, allows remote attackers to inject arbitrary web script or HTML via vectors related to uploader/assets/uploader.swf.

Cross-site scripting (XSS) vulnerability in the Flash component infrastructure in YUI 2.4.0 through 2.8.1, as used in Bugzilla, Moodle, and other products, allows remote attackers to inject arbitrary web script or HTML via vectors related to charts/assets/charts.swf.

SQL injection vulnerability in ing/blocks/mrbs/code/web/view_entry.php in the MRBS plugin for Moodle allows remote attackers to execute arbitrary SQL commands via the id parameter.