CVE-2021-25735

Validating Admission Webhook does not observe some previous fields

Description

A security issue was discovered in kube-apiserver that could allow node updates to bypass a Validating Admission Webhook. Clusters are only affected by this vulnerability if they run a Validating Admission Webhook for Nodes that denies admission based at least partially on the old state of the Node object. Validating Admission Webhook does not observe some previous fields.

Category

6.5
CVSS
Severity: Medium
CVSS 3.1 •
CVSS 2.0 •
EPSS 18.45% Top 10%
Third-Party Advisory github.com Third-Party Advisory google.com
Affected: Kubernetes Kubernetes
Published at:
Updated at:

References

Link Tags
https://groups.google.com/g/kubernetes-security-announce/c/FKAGqT4jx9Y third party advisory mailing list
https://github.com/kubernetes/kubernetes/issues/100096 third party advisory patch

Frequently Asked Questions

What is the severity of CVE-2021-25735?
CVE-2021-25735 has been scored as a medium severity vulnerability.
How to fix CVE-2021-25735?
To fix CVE-2021-25735, make sure you are using an up-to-date version of the affected component(s) by checking the vendor release notes. As for now, there are no other specific guidelines available.
Is CVE-2021-25735 being actively exploited in the wild?
It is possible that CVE-2021-25735 is being exploited or will be exploited in a near future based on public information. According to its EPSS score, there is a ~18% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
What software or system is affected by CVE-2021-25735?
CVE-2021-25735 affects Kubernetes Kubernetes.
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