Vulnerabilities > CVE-2020-8561 - Externally Controlled Reference to a Resource in Another Sphere vulnerability in Kubernetes 1.20.11/1.21.5/1.22.2

047910
CVSS 4.1 - MEDIUM
Attack vector
NETWORK
Attack complexity
LOW
Privileges required
HIGH
Confidentiality impact
LOW
Integrity impact
NONE
Availability impact
NONE
network
low complexity
kubernetes
CWE-610
NVD
Published: 2021-09-20
Updated: 2024-11-21

Summary

A security issue was discovered in Kubernetes where actors that control the responses of MutatingWebhookConfiguration or ValidatingWebhookConfiguration requests are able to redirect kube-apiserver requests to private networks of the apiserver. If that user can view kube-apiserver logs when the log level is set to 10, they can view the redirected responses and headers in the logs.

Vulnerable Configurations

Part Description Count
Application
Kubernetes
3

Common Weakness Enumeration (CWE)

Common Attack Pattern Enumeration and Classification (CAPEC)

  • XML Routing Detour Attacks
    An attacker subverts an intermediate system used to process XML content and forces the intermediate to modify and/or re-route the processing of the content. XML Routing Detour Attacks are Man in the Middle type attacks. The attacker compromises or inserts an intermediate system in the processing of the XML message. For example, WS-Routing can be used to specify a series of nodes or intermediaries through which content is passed. If any of the intermediate nodes in this route are compromised by an attacker they could be used for a routing detour attack. From the compromised system the attacker is able to route the XML process to other nodes of his or her choice and modify the responses so that the normal chain of processing is unaware of the interception. This system can forward the message to an outside entity and hide the forwarding and processing from the legitimate processing systems by altering the header information.

References