CVE-2021-25735 is a vulnerability in Kubernetes
Published on September 6, 2021
Validating Admission Webhook does not observe some previous fields
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.
Vulnerability Analysis
CVE-2021-25735 can be exploited with network access, and requires user privileges. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to have no impact on confidentiality, a high impact on integrity and availability.
Weakness Type
Incomplete Internal State Distinction
The software does not properly determine which state it is in, causing it to assume it is in state X when in fact it is in state Y, causing it to perform incorrect operations in a security-relevant manner.
Products Associated with CVE-2021-25735
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Affected Versions
Kubernetes:- Version unspecified, <= 1.18.17 is affected.
- Version unspecified, <= 1.19.9 is affected.
- Version unspecified, <= 1.20.5 is affected.
Exploit Probability
EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.