CVE-2020-28970: Westerndigital My Cloud OS 5

Critical severity, CVSS 9.8. EPSS: 3.9% chance of exploitation in the next 30 days.

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)

Published 2020-12-01. Last modified 2026-06-17.