CVE-2021-32783 Detail

Current Description

Contour is a Kubernetes ingress controller using Envoy proxy. In Contour before version 1.17.1 a specially crafted ExternalName type Service may be used to access Envoy's admin interface, which Contour normally prevents from access outside the Envoy container. This can be used to shut down Envoy remotely (a denial of service), or to expose the existence of any Secret that Envoy is using for its configuration, including most notably TLS Keypairs. However, it *cannot* be used to get the *content* of those secrets. Since this attack allows access to the administration interface, a variety of administration options are available, such as shutting down the Envoy or draining traffic. In general, the Envoy admin interface cannot easily be used for making changes to the cluster, in-flight requests, or backend services, but it could be used to shut down or drain Envoy, change traffic routing, or to retrieve secret metadata, as mentioned above. The issue will be addressed in Contour v1.18.0 and a cherry-picked patch release, v1.17.1, has been released to cover users who cannot upgrade at this time. For more details refer to the linked GitHub Security Advisory.


View Analysis Description

Severity



CVSS 3.x Severity and Metrics:

NIST CVSS score matches with CNA score
CNA:  GitHub, Inc.
Base Score:  8.5 HIGH
Vector:  CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:N/A:H


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Note: The NVD and the CNA have provided the same score. When this occurs only the CNA information is displayed, but the Acceptance Level icon for the CNA is given a checkmark to signify NVD concurrence.

References to Advisories, Solutions, and Tools

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Hyperlink Resource
https://github.com/projectcontour/contour/commit/b53a5c4fd927f4ea2c6cf02f1359d8e28bef852e Patch  Third Party Advisory 
https://github.com/projectcontour/contour/releases/tag/v1.17.1 Release Notes  Third Party Advisory 
https://github.com/projectcontour/contour/security/advisories/GHSA-5ph6-qq5x-7jwc Third Party Advisory 

Weakness Enumeration

CWE-ID CWE Name Source
CWE-610 Externally Controlled Reference to a Resource in Another Sphere cwe source acceptance level NIST  
CWE-441 Unintended Proxy or Intermediary ('Confused Deputy') Contributor acceptance level GitHub, Inc.  

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Change History

1 change records found show changes

Quick Info

CVE Dictionary Entry:
CVE-2021-32783
NVD Published Date:
07/23/2021
NVD Last Modified:
08/05/2021
Source:
GitHub, Inc.