CVE-2021-20185: moodle Uncontrolled Resource Consumption
Modified
AliasesUBUNTU-CVE-2021-20185
Published 28-01-2021Last modified 03-08-2024
Vulnerability summary
CVE-2021-20185 is a medium (CVSS 5.3) Uncontrolled Resource Consumption vulnerability in moodle. EPSS estimates a 1.38% chance of exploitation in the next 30 days, higher than 71.8% of scored vulnerabilities.
CVSS score
5.3/10
010
Medium · v3.1 (NVD)EPSS score
1.38%
0%100%
Low · 0.00 pp in 30 daysKEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded
Timeline
- 28-01-2021PublishedVulnerability first disclosed.
- 03-08-2024Last modifiedVulnerability information updated.
Description
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.
CVSS metrics
3 scores · 2 sources · 2 versionsMedium 5.3Preferred score · NVD (NIST)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:LSourcesAll 2 agree
- OSV · UbuntuEcosystem advisory · calculated5.3MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
Medium 5.0Preferred score · NVD (NIST)
AV:N/AC:L/Au:N/C:N/I:N/A:PSourcesSingle source
EPSS trend
Probability
1.38%
Chance of exploitation in the next 30 days
Percentile
72%
Versus all other CVEs
30-day change
No change 0.00 pp
From 1.38% on 22-09-2026
22-09-202622-10-2026
Known exploited
Compare KEV catalogs
CISA KEVNot in the CISA KEV catalog.
ENISA CNWNot in the ENISA CNW catalog.
CIRCLNot in the CIRCL catalog.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root cause- CWE-400Uncontrolled Resource ConsumptionThe product does not properly control the allocation and maintenance of a limited resource.
- CWE-770Allocation of Resources Without Limits or ThrottlingThe product allocates a reusable resource or group of resources on behalf of an actor without imposing any intended restrictions on the size or number of resources that can be allocated.
Affected systems
Moodle1 product
- moodleEOL≥ 3.5.0, < 3.5.16 | ≥ 3.8.0, < 3.8.7 | ≥ 3.9.0, < 3.9.4 | 3.10.0
Ubuntu1 product
- moodleAll versions (No fix recorded)
2 vendors · 2 products