CVE-2021-25735

MEDIUM severity · CVSS 6.5 · CWE-372

6.5CVSS MEDIUM

Summary

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.

Impact & exploitability

Attack vectorNetwork

Attack complexityLow

Privileges requiredHigh

User interactionNone

Confidentiality impactNone

Integrity impactHigh

Availability impactHigh

Exploit probability (EPSS)16%

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

Affected products we track (1)

Kubernetes

Recommendation

Apply the vendor fix in your normal patch cycle. Open any affected product above for its exact safe version.

Official patch: https://github.com/kubernetes/kubernetes/issues/100096 ↗

Additional information

NVD record
https://github.com/kubernetes/kubernetes/issues/100096Patch
https://github.com/kubernetes/kubernetes/issues/100096Patch
https://groups.google.com/g/kubernetes-security-announce/c/FKAGqT4jx9YAdvisory
https://groups.google.com/g/kubernetes-security-announce/c/FKAGqT4jx9YAdvisory