CVE•Published 2021-09-20•Modified 2026-06-01•0 articles on news•6 live references•NVD data

CVE-2020-8561Kubernetes · Kubernetes

Vulnerability data via NVD (ingested)

CVSS v3.1

4.1

MEDIUM

CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:L/I:N/A:N

EPSS percentile

Exploit Prediction Scoring System · top 60% of all CVEs

Weaknesses (CWE)

CWE-441Unintended Proxy or Intermediary ('Confused Deputy')CWE-610Externally Controlled Reference to a Resource in Another Sphere

Description

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.

Timeline

Published 2021-09-20

Modified 2026-06-01

External references

NVD MITRE Exploit-DB Sploitus trickest/cve VulnCheck

Search for exposed instances

Shodan + Censys queries derived from NVD's CPE data. The vuln tag catches assets Shodan has explicitly linked to this CVE; the product / banner fingerprints find exposed instances even when the vuln tag was never applied (which is common).

Shodan · vuln tag0 hosts

vuln:CVE-2020-8561

Hosts Shodan has explicitly fingerprinted as vulnerable.

Shodan · product + version

product:"Kubernetes Kubernetes" version:"1.20.11"

Version-pinned fingerprint from NVD's first vulnerable CPE.

Shodan · banner/body mention

http.html:"Kubernetes"

HTTP body or banner mentions "Kubernetes" — catches deploys Shodan didn't identify as a product.

More intel sources (5)

Shodan report

vuln:CVE-2020-8561