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Kube-proxy may unintentionally forward traffic

Moderate severity GitHub Reviewed Published Oct 30, 2023 to the GitHub Advisory Database • Updated Nov 9, 2023

Package

gomod k8s.io/kubernetes (Go)

Affected versions

< 1.21

Patched versions

1.21

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.

References

Published by the National Vulnerability Database Oct 30, 2023
Published to the GitHub Advisory Database Oct 30, 2023
Reviewed Oct 31, 2023
Last updated Nov 9, 2023

Severity

Moderate

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Network
Attack complexity
High
Privileges required
High
User interaction
None
Scope
Changed
Confidentiality
High
Integrity
None
Availability
None

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:C/C:H/I:N/A:N

EPSS score

0.124%
(48th percentile)

Weaknesses

No CWEs

CVE ID

CVE-2021-25736

GHSA ID

GHSA-35c7-w35f-xwgh

Source code

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