Western Digital blocks unpatched My Cloud devices

Western Digital has blocked devices running vulnerable firmware versions from accessing its cloud services, the company said in an advisory.

The move comes about a month after the company released firmware updates for its My Cloud product line to address a critical path traversal bug that leads to remote code execution (RCE).

“Devices running unpatched firmware versions will not be able to connect to Western Digital cloud services starting June 15, 2023, and users will not be able to access their data until the device updates to the latest firmware,” the company said.

Users can, however, continue to access their data via Local Access, the procedure that enables access through network-mapped drives on a local network.

Flaw patched in May

The issue, tracked as CVE-2022-36327 with 9.8 CVSS severity, could allow an attacker to write files to locations with certain filesystem types leading to remote code execution in Western Digital My Cloud Home, My Cloud Home Duo, ScanDisk ibi and Western Digital My Cloud OS 5 devices.

The vulnerability required an authentication bypass issue to be triggered before it could be exploited. It affected My Cloud Home and My Cloud Home Duo: before 9.4.0-191, ScanDisk ibi: before 9.4.0-191, and My Cloud OS 5: before 5.26.202.

Western Digital released My Cloud OS 5 firmware version 5.26.202 on May 15, which addressed this bug and three other medium-severity issues. These other issues included uncontrolled resource consumption leading to denial-of-service (DoS), path traversal leading to sensitive information disclosure, and server-side request forgery (SSRF) bugs that can lead to the exploitation of other vulnerabilities.

On May 25, the company released firmware version 9.4.1-101 to resolve the SSRF bug in My Cloud Home, My Cloud Home Duo, and SanDisk ibi devices.

Possibly exploited by BlackCat

Last month, ransomware group BlackCat released a set of screenshots on its leak site that it claimed were from data stolen from the Western Digital breach.

The images included screenshots of videoconferences and internal emails of the company. The screenshots also included an image of a recent meeting held by Western Digital where the company was discussing how to respond to the cyberattack.

Western Digital had disclosed the April 3 incident as a network breach where an unauthorized third party gained access to several of the company’s systems. The company had also said that it was taking down certain systems and services offline as a proactive security measure.

These systems included My Cloud, My Cloud Home, My Cloud Home Duo, My Cloud OS 5, and ScanDisk ibi services as several users reported temporarily losing access to them. Following the release of screenshots, BlackCat posted a note stating it would eventually put Western Digital’s intellectual property on sale. There were no further updates on the issue thereon, with no confirmation of any ransom demanded.