CVE-2021-43559

Severity: high (CVSS 8.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.6% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2021-11-22 · updated 2026-06-17
Weakness: CWE-352

Description

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. The "delete related badge" functionality did not include the necessary token check to prevent a CSRF risk.

Affected products

Fedoraproject Extra Packages For Enterprise Linux: 7.0
Fedoraproject Fedora: 35
Moodle: through 3.8.8; from 3.9.0 before 3.9.11; from 3.10.0 before 3.10.8; from 3.11.0 before 3.11.4 — fixed in 3.10.8, 3.11.4, 3.9.11

How to fix

Upgrade to a fixed version: Moodle 3.10.8, 3.11.4, 3.9.11. Check the vendor advisory for mitigations.

References

https://bugzilla.redhat.com/show_bug.cgi?id=2021517
https://moodle.org/mod/forum/discuss.php?d=429099
https://bugzilla.redhat.com/show_bug.cgi?id=2021517
https://moodle.org/mod/forum/discuss.php?d=429099

Get alerted when CVE-2021-43559 or the next vulnerability affects your stack