CVE-2020-28970

Severity: critical (CVSS 9.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 3.9% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2020-12-01 · updated 2026-06-17
Weakness: CWE-287

Description

An issue was discovered on Western Digital My Cloud OS 5 devices before 5.06.115. A NAS Admin authentication bypass vulnerability could allow an unauthenticated user to execute privileged commands on the device via a cookie. (In addition, an upload endpoint could then be used by an authenticated administrator to upload executable PHP scripts.)

Affected products

Westerndigital My Cloud Os 5: before 5.06.115 — fixed in 5.06.115

How to fix

Upgrade to a fixed version: Westerndigital My Cloud Os 5 5.06.115. Check the vendor advisory for mitigations.

References

https://support.wdc.com/downloads.aspx?g=907&lang=en#downloads
https://www.westerndigital.com/support/productsecurity/wdc-20009-os5-firmware-5-06-115
https://www.zerodayinitiative.com/advisories/ZDI-20-1448/
https://support.wdc.com/downloads.aspx?g=907&lang=en#downloads
https://www.westerndigital.com/support/productsecurity/wdc-20009-os5-firmware-5-06-115
https://www.zerodayinitiative.com/advisories/ZDI-20-1448/

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