CVE-2021-36395: moodle Uncontrolled Resource Consumption
CVSS: 7.5v3.1HighModified
AliasesUBUNTU-CVE-2021-36395
Published 06-03-2023Last modified 07-03-2025
Vulnerability summary
CVE-2021-36395 is a high (CVSS 7.5) Uncontrolled Resource Consumption vulnerability in moodle. EPSS estimates a 0.73% chance of exploitation in the next 30 days, higher than 53.8% of scored vulnerabilities.
CVSS score
7.5/10
010
High · v3.1 (CVE.org)EPSS score
0.73%
0%100%
Low · 0.00 pp in 30 daysKEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded
Timeline
- 06-03-2023PublishedVulnerability first disclosed.
- 07-03-2025Last modifiedVulnerability information updated.
Description
In Moodle, the file repository's URL parsing required additional recursion handling to mitigate the risk of recursion denial of service.
CVSS metrics
3 scores · 3 sources · 1 versionHigh 7.5Preferred score · CVE.org (CNA)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:HSourcesAll 3 agree
- OSV · UbuntuEcosystem advisory · calculated7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- NVDNIST7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS trend
Probability
0.73%
Chance of exploitation in the next 30 days
Percentile
54%
Versus all other CVEs
30-day change
0.00 pp
From 0.73% on 21-09-2026
21-09-202621-10-2026
EPSS score0.73%
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
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-674Uncontrolled RecursionThe product does not properly control the amount of recursion that takes place, consuming excessive resources, such as allocated memory or the program stack.
Affected systems
Moodle1 product
- moodle< 3.9.8 | ≥ 3.10.0, < 3.10.5 | ≥ 3.11.0, < 3.11.1
Ubuntu1 product
- moodleAll versions (No fix recorded)
2 vendors · 2 products