What is CVE-2021-20186?

CVE-2021-20186 is a medium-severity vulnerability in Moodle, classified under Cross-site Scripting. CVSS score: 5.4/10. Published 2021-01-28.

How severe is CVE-2021-20186?

Medium severity. CVSS v3 base score is 5.4 out of 10.

Is CVE-2021-20186 known to be exploited?

1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.

XSS in Moodle

CVE-2021-20186

It was found in Moodle before version 3.10.1, 3.9.4, 3.8.7 and 3.5.16 that if the TeX notation filter was enabled, additional sanitizing of TeX content was required to prevent the risk of stored XSS.

Vulnerability class: XSS (Cross-Site Scripting)

EPSS: 0.008 (51.3th percentile) — read the EPSS interpretation.

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.

Affected products

Moodle
N/a Moodle — versions moodle 3.10.1, moodle 3.9.4, moodle 3.8.7, moodle 3.5.16

Weakness classification (CWE)

CWE-79 — Cross-site Scripting

Public proof-of-concept exploits

jev770/badmoodle-scan

References

secalert@redhat.com (Patch, x_refsource_MISC, Vendor Advisory)

Frequently asked questions

What is CVE-2021-20186?: CVE-2021-20186 is a medium-severity vulnerability in Moodle, classified under Cross-site Scripting. CVSS score: 5.4/10. Published 2021-01-28.
How severe is CVE-2021-20186?: Medium severity. CVSS v3 base score is 5.4 out of 10.
Is CVE-2021-20186 known to be exploited?: 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.