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CVE-2018-17153: It was discovered that the Western Digital My Cloud device before 2.30.196 is affected by an authentication…

CVE-2018-17153 is rated critical with a CVSS v3.0 base score of 9.8 and NVD lists 12 affected products, including Western Digital My Cloud Wdbctl0020hwt Firmware. Per its scoring, it can be exploited over the network, without authentication, without any user interaction. The scored impact on confidentiality, integrity and availability is the highest available.

Vulnerability description

It was discovered that the Western Digital My Cloud device before 2.30.196 is affected by an authentication bypass vulnerability. An unauthenticated attacker can exploit this vulnerability to authenticate as an admin user without needing to provide a password, thereby gaining full control of the device. (Whenever an admin logs into My Cloud, a server-side session is created that is bound to the user's IP address. After the session is created, it is possible to call authenticated CGI modules by sending the cookie username=admin in the HTTP request. The invoked CGI will check if a valid session is present and bound to the user's IP address.) It was found that it is possible for an unauthenticated attacker to create a valid session without a login. The network_mgr.cgi CGI module contains a command called "cgi_get_ipv6" that starts an admin session -- tied to the IP address of the user making the request -- if the additional parameter "flag" with the value "1" is provided. Subsequent invocation of commands that would normally require admin privileges now succeed if an attacker sets the username=admin cookie.

Severity breakdown

CVSS v3.0 9.8: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

  • Attack vector: Network. Exploitable remotely over the network, with no need for local or physical access.
  • Attack complexity: Low. No special conditions; the attack can be repeated reliably.
  • Privileges required: None. No account or prior access is needed.
  • User interaction: None. No action from any user is needed.
  • Scope: Unchanged. Impact stays within the vulnerable component.
  • Confidentiality impact: High. Total loss of confidentiality; sensitive data can be fully disclosed.
  • Integrity impact: High. Total loss of integrity; data or system state can be fully modified.
  • Availability impact: High. Total loss of availability; the component can be shut down.

Underlying weakness

CWE-287: Improper Authentication

When an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct.

Affected products

  • Western Digital My Cloud Wdbctl0020hwt Firmware: before 2.30.196
  • Western Digital My Cloud Pr4100: before 2.30.196
  • Western Digital My Cloud Pr2100 Firmware: before 2.30.196
  • Western Digital My Cloud Mirror Gen 2 Firmware: before 2.30.196
  • Western Digital My Cloud Mirror Firmware: before 2.30.196
  • Western Digital My Cloud Ex4100: before 2.30.196
  • Western Digital My Cloud Ex4 Firmware: before 2.30.196
  • Western Digital My Cloud Ex2100 Firmware: before 2.30.196
  • Western Digital My Cloud Ex2 Ultra Firmware: before 2.30.196
  • Western Digital My Cloud Ex2 Firmware: before 2.30.196
  • Western Digital My Cloud Dl4100 Firmware: before 2.30.196
  • Western Digital My Cloud Dl2100: before 2.30.196

References