Cyber Resilience

CVE-2021-36400

Medium

Published: 06 March 2023

Published
06 March 2023
Modified
07 March 2025
KEV Added
Patch
CVSS Score v3.1 5.3 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
EPSS Score 0.0028 51.7th percentile
Risk Priority 11 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2021-36400 is a medium-severity Incorrect Default Permissions (CWE-276) vulnerability in Moodle Moodle. Its CVSS base score is 5.3 (Medium).

Operationally, ranked in the top 48.3% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability details

In Moodle, insufficient capability checks made it possible to remove other users' calendar URL subscriptions.

CWE(s)

Related Threats

No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.

Affected Assets

moodle
moodle
≤ 3.9.8 · 3.10.0 — 3.10.5 · 3.11.0 — 3.11.1

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-276

Access control policy can specify and enforce secure default permissions for resources.

addresses: CWE-639

Per-request decision making makes it harder to bypass authorization using user-controlled keys without proper validation in the decision process.

addresses: CWE-639

Consistent enforcement of approved authorizations makes bypassing via user-controlled keys ineffective.

addresses: CWE-276

Guides setting of default permissions to the minimum required level.

addresses: CWE-276

Establishes requirements for appropriate default permissions on system resources as part of configuration management.

addresses: CWE-276

Baseline establishment and updates on install/upgrade ensure correct default permissions rather than insecure ones.

addresses: CWE-276

Requiring the most restrictive settings instead of defaults prevents incorrect default permissions on resources.

addresses: CWE-276

Requires documented processes that include setting and maintaining correct default permissions for configuration items.

References