Persistent XSS in /course/modedit.php of Moodle through 3.7.2 allows authenticated users (Teacher and above) to inject JavaScript into the session of another user (e.g., enrolled student or site administrator) via the introeditor[text] parameter. NOTE: the discoverer and vendor disagree on whether Moodle customers have a reasonable expectation that anyone authenticated as a Teacher can be trusted with the ability to add arbitrary JavaScript (this ability is not documented on Moodle's Teacher_role page). Because the vendor has this expectation, they have stated "this report has been closed as a false positive, and not a bug."

References

• https://nvd.nist.gov/vuln/detail/CVE-2019-18210
• https://docs.moodle.org/38/en/Teacher_role
• https://gist.github.com/Danbardo/4a6b0fe8cb21ec6d7c54e6ac951bdb0a