CVE-2021-25736

Windows kube-proxy LoadBalancer contention

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.

Remediation

Solution:

This issue has been fixed in the following versions: * v1.21.0 * v1.20.6 * v1.19.10 * v1.18.18

5.8

CVSS

Severity: Medium

CVSS 3.1 •

EPSS 0.12%

Third-Party Advisory github.com Third-Party Advisory google.com

Affected: Kubernetes Kubernetes

References

Link	Tags
https://github.com/kubernetes/kubernetes/pull/99958	third party advisory
https://groups.google.com/g/kubernetes-security-announce/c/lIoOPObO51Q/m/O15LOazPAgAJ	third party advisory mailing list
https://security.netapp.com/advisory/ntap-20231221-0003/

Frequently Asked Questions

What is the severity of CVE-2021-25736?: CVE-2021-25736 has been scored as a medium severity vulnerability.
How to fix CVE-2021-25736?: To fix CVE-2021-25736: This issue has been fixed in the following versions: * v1.21.0 * v1.20.6 * v1.19.10 * v1.18.18
Is CVE-2021-25736 being actively exploited in the wild?: As for now, there are no information to confirm that CVE-2021-25736 is being actively exploited. According to its EPSS score, there is a ~0% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
What software or system is affected by CVE-2021-25736?: CVE-2021-25736 affects Kubernetes Kubernetes.

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