What is CVE-2021-3943?

CVE-2021-3943 is a critical-severity vulnerability in Moodle, classified under Improper Input Validation. CVSS score: 9.8/10. Published 2021-11-22.

How severe is CVE-2021-3943?

Critical severity. CVSS v3 base score is 9.8 out of 10.

Is CVE-2021-3943 known to be exploited?

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

Improper input validation in Moodle

CVE-2021-3943

A flaw was found in Moodle in versions 3.11 to 3.11.3, 3.10 to 3.10.7, 3.9 to 3.9.10 and earlier unsupported versions. A remote code execution risk when restoring backup files was identified.

Vulnerability class: Drupalgeddon 2 (CVE-2018-7600)

EPSS: 0.024 (82.1th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

Affected products

Moodle
N/a Moodle — versions moodle 3.11.4, moodle 3.10.8 and moodle 3.9.11

Weakness classification (CWE)

CWE-20 — Improper Input Validation

Public proof-of-concept exploits

jev770/badmoodle-scan

References

patrick@puiterwijk.org (Third Party Advisory, x_refsource_MISC, Issue Tracking)
patrick@puiterwijk.org (Patch, x_refsource_MISC, Vendor Advisory)

Frequently asked questions

What is CVE-2021-3943?: CVE-2021-3943 is a critical-severity vulnerability in Moodle, classified under Improper Input Validation. CVSS score: 9.8/10. Published 2021-11-22.
How severe is CVE-2021-3943?: Critical severity. CVSS v3 base score is 9.8 out of 10.
Is CVE-2021-3943 known to be exploited?: 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.