Advisory Details

February 15th, 2022

(Pwn2Own) Western Digital MyCloud PR4100 cgi_api Server-Side Request Forgery Privilege Escalation Vulnerability

ZDI-22-348
ZDI-CAN-15889

CVE ID CVE-2022-22993
CVSS SCORE 8.0, (AV:A/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H)
AFFECTED VENDORS Western Digital
AFFECTED PRODUCTS MyCloud PR4100
VULNERABILITY DETAILS

This vulnerability allows network-adjacent attackers to escalate privileges on affected installations of Western Digital MyCloud PR4100. Although authentication is required to exploit this vulnerability, the existing authentication mechanism can be bypassed.

The specific flaw exists within the cgi_api endpoint. The issue results from the lack of proper validation of URIs prior to accessing resources. An attacker can leverage this in conjunction with other vulnerabilities to execute arbitrary code in the context of root.

ADDITIONAL DETAILS Western Digital has issued an update to correct this vulnerability. More details can be found at:
https://www.westerndigital.com/support/product-security/wdc-22002-my-cloud-os5-firmware-5-19-117
DISCLOSURE TIMELINE
  • 2021-12-01 - Vulnerability reported to vendor
  • 2022-02-15 - Coordinated public release of advisory
CREDIT Sam Thomas (@_s_n_t) of Pentest Ltd (@pentestltd)
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