CVE-2020-8559

MEDIUM

Kubernetes <v1.16.13,v1.17.9,v1.18.6 - Open Redirect

Title source: llm
STIX 2.1

Exploitation Summary

EIP tracks 2 public exploits for CVE-2020-8559. PoCs published by tdwyer, tabbysable.

AI-analyzed exploit summary This repository provides a functional proof-of-concept exploit for CVE-2020-8559, which allows an attacker with root access on a Kubernetes node to execute commands on other containers in the cluster by leveraging HTTP redirects in the kubelet server. The exploit involves modifying the kubelet binary to send malicious 302 redirects when specific API paths are accessed.

Description

The Kubernetes kube-apiserver in versions v1.6-v1.15, and versions prior to v1.16.13, v1.17.9 and v1.18.6 are vulnerable to an unvalidated redirect on proxied upgrade requests that could allow an attacker to escalate privileges from a node compromise to a full cluster compromise.

Exploits (2)

nomisec WORKING POC 54 stars
by tdwyer · poc
https://github.com/tdwyer/CVE-2020-8559

This repository provides a functional proof-of-concept exploit for CVE-2020-8559, which allows an attacker with root access on a Kubernetes node to execute commands on other containers in the cluster by leveraging HTTP redirects in the kubelet server. The exploit involves modifying the kubelet binary to send malicious 302 redirects when specific API paths are accessed.

Classification
Working Poc 95%
Attack Type
Rce
Complexity
Moderate
Reliability
Reliable
Target: Kubernetes v1.15.9
Auth required
Prerequisites: Root access on a Kubernetes node · Ability to replace the kubelet binary
devstral-2 · analyzed Feb 18, 2026 Full analysis →
nomisec WORKING POC 20 stars
by tabbysable · poc
https://github.com/tabbysable/POC-2020-8559

This repository contains a functional exploit for CVE-2020-8559, which manipulates iptables to intercept and redirect Kubernetes kubelet traffic, bypassing authentication by rewriting HTTP responses. The script uses OpenSSL to ferry TLS connections and modify response codes to achieve unauthorized access.

Classification
Working Poc 95%
Attack Type
Auth Bypass
Complexity
Moderate
Reliability
Reliable
Target: Kubernetes kubelet (versions affected by CVE-2020-8559)
No auth needed
Prerequisites: Access to a host with iptables and OpenSSL · Kubernetes cluster with vulnerable kubelet configuration
devstral-2 · analyzed Feb 18, 2026 Full analysis →

References (3)

Core 3
Core References
Exploit, Issue Tracking, Patch, Third Party Advisory x_refsource_misc
https://github.com/kubernetes/kubernetes/issues/92914
Third Party Advisory x_refsource_confirm
https://security.netapp.com/advisory/ntap-20200810-0004/

Scores

CVSS v3 6.4
EPSS 0.5120
EPSS Percentile 97.9%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:U/C:H/I:H/A:H

Details

CWE
CWE-601
Status published
Products (3)
k8s.io/apimachinery 0 - 0.16.13Go
k8s.io/kubernetes 0 - 1.16.13Go
kubernetes/kubernetes 1.6.0 - 1.15.0
Published Jul 22, 2020
Tracked Since Feb 18, 2026