Cyber Resilience

CVE-2021-36225

HighPublic PoC

Published: 06 February 2023

Published
06 February 2023
Modified
26 March 2025
KEV Added
Patch
CVSS Score v3.1 8.8 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.0036 58.4th percentile
Risk Priority 18 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2021-36225 is a high-severity Missing Authorization (CWE-862) vulnerability in Westerndigital My Cloud Os. Its CVSS base score is 8.8 (High).

Operationally, ranked in the top 41.6% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

EU & UK References

Vulnerability details

Western Digital My Cloud devices before OS5 allow REST API access by low-privileged accounts, as demonstrated by API commands for firmware uploads and installation.

CWE(s)

Related Threats

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

Affected Assets

westerndigital
my cloud os
≤ 5.02.104

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-862

Requiring an access control policy ensures authorization checks are defined and applied for critical functions.

addresses: CWE-862

Reviews of access controls detect missing authorization checks on critical functions or resources.

addresses: CWE-862

Documenting permitted unauthenticated actions prevents missing authorization by making all exceptions explicit and subject to organizational review.

addresses: CWE-862

Requiring attribute association with information prevents authorization from being performed without necessary security or privacy context.

addresses: CWE-862

Mandating authorization prior to allowing remote connections addresses missing authorization for remote access.

addresses: CWE-862

Mandating authorization before wireless connections are allowed prevents missing authorization for wireless access.

addresses: CWE-862

The control requires authorization before allowing mobile device connections, directly mitigating missing authorization for system access.

addresses: CWE-862

Requiring approvals for account creation and specifying authorizations ensures authorization is not missing for system access.

References