Resource exhaustion in Moodle

CVE-2021-20185

It was found in Moodle before version 3.10.1, 3.9.4, 3.8.7 and 3.5.16 that messaging did not impose a character limit when sending messages, which could result in client-side (browser) denial of service for users receiving very large messages.

Vulnerability class: DoS (Denial of Service)

Published · last modified .

CVSS v3 metric

CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L.

EPSS exploit prediction

EPSS: 0.014 (71.1th percentile), scored .

Low probability of exploitation in the next 30 days, but still tracked. 71st percentile — 71.1% 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-2021-20185: held from 0.014 to 0.014.

EPSS over last 30 days · oldest: 0.014 · newest: 0.014 · change: 0.000

Affected products

  • Moodle — versions 3.10.0
  • Moodle — versions moodle 3.10.1, moodle 3.9.4, moodle 3.8.7, moodle 3.5.16

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2021-20185?
CVE-2021-20185 is a medium-severity vulnerability in Moodle, classified under Uncontrolled Resource Consumption. CVSS score: 5.3/10. Published 2021-01-28.
How severe is CVE-2021-20185?
Medium severity. CVSS v3 base score is 5.3 out of 10.
Is CVE-2021-20185 known to be exploited?
1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.