CVE-2021-25736 - CVE House
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Status published Medium CVE-2021-25736

Windows kube-proxy LoadBalancer contention

Vulnerability Description

Kube-proxy on Windows can unintentionally forward traffic to local processes listening on the same port (“spec.ports[*].port”) as a LoadBalancer Service when the LoadBalancer controller does not set the “status.loadBalancer.ingress[].ip” field. Clusters where the LoadBalancer controller sets the “status.loadBalancer.ingress[].ip” field are unaffected.

Impact Analysis

Refer to official advisory for detailed impact metrics.

Remediation

Ensure systems are updated to the latest vendor-supplied patch levels.

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Credits & Attribution

The following person or organization is credited with identifying this vulnerability, as recorded in the NVD database:

  • Eric Paris
  • Christian Hernandez

References

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Affected Vendor

Affected Software

Kubernetes
Vulnerable Versions:
0

Timeline

Official Publish: October 30th, 2023
Last Modified: June 12th, 2025
Added to House: July 21st, 2026

CVSS Vectors

V3: CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:C/C:H/I:N/A:N

Weaknesses (CWE)

No CWE data available

MITRE ATT&CK TTPs

No associated TTPs found for this vulnerability.