CVE-2021-25735

Description

A vulnerability was found in Kubernetes' kube-apiserver that could allow Node updates to bypass a Validating Admission Webhook. An authenticated user could exploit this by modifying Node properties to values that should have been prevented by registered admission webhooks.

Common Vulnerability Scoring System (CVSS) Score Details

Info alert:Important note

CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).

CVSS v3 Score Breakdown

Red HatNVDcve.org
Base Score6.56.56.5
Attack VectorNetworkNetworkNetwork
Attack ComplexityLowLowLow
Privileges RequiredHighHighHigh
User InteractionNoneNoneNone
ScopeUnchangedUnchangedUnchanged
ConfidentialityNoneNoneNone
Integrity ImpactHighHighHigh
Availability ImpactHighHighHigh

Vector

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

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

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

Understanding the Weakness (CWE)

Availability

Technical Impact: DoS: Crash, Exit, or Restart; DoS: Resource Consumption (CPU); DoS: Resource Consumption (Memory)

An attacker could provide unexpected values and cause a program crash or arbitrary control of resource allocation, leading to excessive consumption of resources such as memory and CPU.

Confidentiality

Technical Impact: Read Memory; Read Files or Directories

An attacker could read confidential data if they are able to control resource references.

Integrity,Confidentiality,Availability

Technical Impact: Modify Memory; Execute Unauthorized Code or Commands

An attacker could use malicious input to modify data or possibly alter control flow in unexpected ways, including arbitrary command execution.

Acknowledgements

Red Hat would like to thank the Kubernetes Product Security Committee for reporting this issue. Upstream acknowledges Ari Lima (Red Hat) and Rogerio Bastos (Red Hat) as the original reporters.

Frequently Asked Questions

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