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CVE-2021-25736

Windows kube-proxy LoadBalancer contention

Published: Oct 30, 2023Updated: Jun 12, 2025 Sources: CVE List NVD GHSANVD-CWE-noinfo
NVD MITRE
5.8CVSSMEDIUM
EPSS Score
0.9%
Top 44.8%
CISA KEV
Not in KEV
Exploits
No Known Exploits
Remediation
Patch Available

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.

CVSS Vector Breakdown

AV:NAC:HPR:HUI:NS:CC:HI:NA:N
Exploitability
AV:NAttack Vector
Network
AC:HAttack Complexity
High
PR:HPrivileges Required
High
UI:NUser Interaction
None
Scope
S:CScope
Changed
Impact
C:HConfidentiality
High
I:NIntegrity
None
A:NAvailability
None
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Weaknesses

NVD-CWE-noinfoCWE-114

Affected Products

kuberneteskubernetes
On-premDev Tool
Cloud & SaaS / container-orchestration
k8s.io/kubernetesGoOSS Libraries
KubernetesKubernetes
On-premDev Tool
Cloud & SaaS / container-orchestration
kubernetesoss-projectUSCloud & SaaSaka k8s
gopackage-ecosystemOSS Libraries

Exploitability

Official Patch Available

References

https://github.com/kubernetes/kubernetes/pull/99958
github.com
https://groups.google.com/g/kubernetes-security-announce/c/lIoOPObO51Q/m/O15LOazPAgAJ
groups.google.com
https://security.netapp.com/advisory/ntap-20231221-0003/
security.netapp.com
and 4 more references View all →

Timeline

Published
Oct 30, 2023
Last Updated
Jun 12, 2025

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