Quantum Secular Labs / Blog / Advisories

CVE-2017-20174: Getkirby Webmentions: Improper Neutralization of Special Elements in Output Used by a Downstream Component

CVE-2017-20174 is rated critical with a CVSS v3.1 base score of 9.8 and affects Getkirby Webmentions. 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

A vulnerability was found in bastianallgeier Kirby Webmentions Plugin and classified as problematic. Affected by this issue is some unknown functionality. The manipulation leads to injection. The attack may be launched remotely. The complexity of an attack is rather high. The exploitation is known to be difficult. The patch is identified as 55bedea78ae9af916a9a41497bd9996417851502. It is recommended to apply a patch to fix this issue. VDB-218894 is the identifier assigned to this vulnerability.

Severity breakdown

CVSS v3.1 9.8: CVSS:3.1/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-74: Improper Neutralization of Special Elements in Output Used by a Downstream Component

The product constructs all or part of a command, data structure, or record using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify how it is parsed or interpreted when it is sent to a downstream component.

Affected products

  • Getkirby Webmentions: before 2017-02-01

References