CVE-2021-25736

MediumCVSS 6.3/10Last modified Jun 17, 2026

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.

Metrics

CVSS 3.1 6.3/10CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:N/A:N

Weakness enumeration

CWE-114

Affected software

Vendor	Product	Versions
Kubernetes	Kubernetes	<= v1.20.5

References

https://github.com/kubernetes/kubernetes/pull/99958Third Party Advisory
https://groups.google.com/g/kubernetes-security-announce/c/lIoOPObO51Q/m/O15LOazPAgAJMailing List, Third Party Advisory
https://security.netapp.com/advisory/ntap-20231221-0003/
https://github.com/kubernetes/kubernetes/pull/99958Third Party Advisory
https://groups.google.com/g/kubernetes-security-announce/c/lIoOPObO51Q/m/O15LOazPAgAJMailing List, Third Party Advisory
https://security.netapp.com/advisory/ntap-20231221-0003/

Timeline

Published: Oct 30, 2023
Last modified: Jun 17, 2026
NVD status: Modified

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