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.
Moodle 3.10.1 is vulnerable to persistent/stored cross-site scripting (XSS) due to the improper input sanitization on the "Additional HTML Section" via "Header and Footer" parameter in /admin/settings.php. This vulnerability is leading an attacker to steal admin and all user account cookies by storing the malicious XSS payload in Header and Footer. NOTE: this is disputed by the vendor because the "Additional HTML Section" for "Header and Footer" can only be supplied by an administrator, who is intentionally allowed to enter unsanitized input (e.g., site-specific JavaScript).
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.