vulnerability

Kubernetes: CVE-2021-25735: Validating Admission Webhook does not observe some previous fields

Severity
6
CVSS
(AV:N/AC:L/Au:S/C:N/I:P/A:P)
Published
Sep 6, 2021
Added
Mar 10, 2022
Modified
Aug 11, 2025

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.

Solutions

kubernetes-upgrade-1_18_18kubernetes-upgrade-1_19_10kubernetes-upgrade-1_20_6
Title
NEW

Explore Exposure Command

Confidently identify and prioritize exposures from endpoint to cloud with full attack surface visibility and threat-aware risk context.