XSS in Moodle

CVE-2019-18210

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."

Vulnerability class: XSS (Cross-Site Scripting)

Published · last modified .

CVSS v3 metric

CVSS v3 base score 5.4 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N.

EPSS exploit prediction

EPSS: 0.008 (55.9th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 56th percentile — 55.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2019-18210: held from 0.008 to 0.008.

EPSS over last 30 days · oldest: 0.008 · newest: 0.008 · change: 0.000

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2019-18210?
CVE-2019-18210 is a medium-severity vulnerability in Moodle, classified under Cross-site Scripting. CVSS score: 5.4/10. Published 2020-02-11.
How severe is CVE-2019-18210?
Medium severity. CVSS v3 base score is 5.4 out of 10.