title: 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.
problem types: CWE-372 Incomplete Internal State Distinction
affected:
{
product: Kubernetes
vendor: Kubernetes
versions:
lessThanOrEqual: 1.18.17, status: affected, version: unspecified, versionType: custom
lessThanOrEqual: 1.19.9, status: affected, version: unspecified, versionType: custom
lessThanOrEqual: 1.20.5, status: affected, version: unspecified, versionType: custom
}
metrics:
cvssV3_1: [
attackComplexity: LOW
attackVector: NETWORK
availabilityImpact: HIGH
baseScore: 6.5
baseSeverity: MEDIUM
confidentialityImpact: NONE
integrityImpact: HIGH
privilegesRequired: HIGH
scope: UNCHANGED
userInteraction: NONE
vectorString: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:H/A:H
version: 3.1
]