In a shared hosting environment that has been misconfigured to allow access to other users' content, a Moodle user with both access to restore database activity modules and direct access to the web server outside of the Moodle webroot could execute a local file include.
Inadequate access control in Moodle LMS. This vulnerability could allow a local user with a student role to create arbitrary events intended for users with higher roles. It could also allow the attacker to add events to the calendar of all users without their prior consent.
In Moodle, in some circumstances, email notifications of messages could have the link back to the original message hidden by HTML, which may pose a phishing risk.