CVE-2020-8559: Privilege escalation from compromised node to cluster
A flaw was found in the Kubernetes API server, where it allows an attacker to escalate their privileges from a compromised node. This flaw allows an attacker who can intercept requests on a compromised node, to redirect those requests, along with their credentials, to perform actions on other endpoints that trust those credentials (including other clusters), allowing for escalation of privileges. The highest threat from this vulnerability is to confidentiality, integrity, and system availability.
Other sources
If an attacker is able to intercept certain requests to the Kubelet, they can send a redirect response that may be followed by a client using the credentials from the original request. This can lead to compromise of other nodes.
— Red Hat
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.
The Kubernetes kube-apiserver in versions v1.6-v1.15, and versions prior to v1.16.13, v1.17.9 and v1.18.7 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.
— GitHub
Affected Software
Remediation
Patch Available
Information
Event History
Parent advisories
This vulnerability appears in the following advisories.
Frequently Asked Questions
What is CVE-2020-8559?
CVE-2020-8559 is a vulnerability in the Kubernetes API server that allows an attacker to escalate their privileges from a compromised node.
What is the severity of CVE-2020-8559?
The severity of CVE-2020-8559 is medium with a CVSS score of 6.4.
Which versions of Kubernetes are affected by CVE-2020-8559?
Versions v1.6-v1.15 and versions prior to v1.16.13, v1.17.9, and v1.18.6 are affected by CVE-2020-8559.
How can I fix CVE-2020-8559?
To fix CVE-2020-8559, update your Kubernetes installation to version v1.16.13, v1.17.9, or v1.18.6.
Where can I find more information about CVE-2020-8559?
You can find more information about CVE-2020-8559 on the CVE website, NIST NVD, Kubernetes Security Announcements, Red Hat Bugzilla, and Red Hat Errata.