Quantum Secular Labs / Blog / Advisories

CVE-2017-17411: Linksys Wvbr0 Firmware: Authentication bypass

CVE-2017-17411 is rated critical with a CVSS v3.0 base score of 9.8 and NVD lists Linksys Wvbr0 Firmware as the affected product. 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

This vulnerability allows remote attackers to execute arbitrary code on vulnerable installations of Linksys WVBR0. Authentication is not required to exploit this vulnerability. The specific flaw exists within the web management portal. The issue lies in the lack of proper validation of user data before executing a system call. An attacker could leverage this vulnerability to execute code with root privileges. Was ZDI-CAN-4892.

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-78: Improper Neutralization of Special Elements used in an OS Command

The product constructs all or part of an OS command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended OS command before it is sent to a downstream component.

Affected products

  • Linksys Wvbr0 Firmware: before 1.0.41

References