CVE-2020-28970: (Pwn2Own) Western Digital MyCloud PR4100 nasAdmin Incorrect Authorization Authentication Bypass Vulnerability
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.)
Other sources
This vulnerability allows network-adjacent attackers to bypass authentication on affected installations of Western Digital MyCloud PR4100. Authentication is not required to exploit this vulnerability. The specific flaw exists within the nasAdmin service, which listens on TCP port 80 and 443 by default. The issue results from incorrect string matching logic when accessing protected pages. An attacker can leverage this vulnerability to execute arbitrary code in the context of root.
Affected Software
Remediation
Event History
Frequently Asked Questions
What is CVE-2020-28970?
CVE-2020-28970 is a vulnerability that allows network-adjacent attackers to bypass authentication on affected installations of Western Digital MyCloud PR4100.
How severe is CVE-2020-28970?
CVE-2020-28970 has a severity rating of 9.8 (Critical).
How does CVE-2020-28970 work?
CVE-2020-28970 exploits a flaw in the nasAdmin service, which listens on TCP port 80 and 443, allowing attackers to bypass authentication.
Which versions of Western Digital MyCloud PR4100 are affected by CVE-2020-28970?
Western Digital MyCloud PR4100 with My Cloud OS 5 up to version 5.06.115 is affected by CVE-2020-28970.
How can I fix CVE-2020-28970?
To fix CVE-2020-28970, update your Western Digital MyCloud PR4100 to firmware version 5.06.115 or higher.