CVE-2021-25736

mediumpriority · track · 25EPSS 0.009 · 60 %ileDEEUUS
grimoire priorityP3 · Track
Exploitable?
—
no known exploitation
Likely / severe?
0.92% (60th) EPSS
CVSS 6.3 · medium
Is it mine?
13 products
Check your exposure
Who says so?
6 sources
cnnvd · enisa_euvd · osv · cert_bund

EPSS · scored 2026-10-23

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.

01

remediations

Vendor fix, mitigation, or workaround guidance, as published by each source.

A vendor fix is available.

  • Fixedopenshift4-wincw/windows-machine-config-operator-bundle@sha256:60ab0ad722725d13abdede0fa569ee4ad2ec95350584dfd51c016510142f0523_amd64 as a component of Red Hat OpenShift Container Platform 4.7redhat_csaf

    For Windows Machine Config Operator upgrades, see the following documentation: https://docs.openshift.com/container-platform/4.7/windows_containers/windows-node-upgrades.html

    https://access.redhat.com/errata/RHSA-2021:2130
  • Fixedopenshift4-wincw/windows-machine-config-rhel8-operator@sha256:34a7784ef1e4cd3aa4a8c2151006ef56a60c8b30c9a7e25cdb198036de8c27e9_amd64 as a component of Red Hat OpenShift Container Platform 4.7redhat_csaf

    For Windows Machine Config Operator upgrades, see the following documentation: https://docs.openshift.com/container-platform/4.7/windows_containers/windows-node-upgrades.html

    https://access.redhat.com/errata/RHSA-2021:2130
02

cvss

Technical severity, 0–10. One row per scoring source.

6.3
010

base score 0–10 · higher = more severe · hover a vector to decode

v3.16.3mediumCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:N/A:Nprimary · NVD / NIST USexploitability 1.8 · impact 4
v3.15.8mediumCVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:C/C:H/I:N/A:Nsecondary · ENISA EU
v3.15.8mediumCVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:C/C:H/I:N/A:Nsecondary · jordan@liggitt.netexploitability 1.3 · impact 4
v3.15.8mediumCVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:C/C:H/I:N/A:Nsecondary · OSV
v3.15.8mediumCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:N/A:N/E:Usecondary · CVSS-BT (t0sche)
v3.15.8mediumCVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:C/C:H/I:N/A:Nsecondary · Red Hat Product Security US
03

ssvc

A stakeholder decision — act, attend, or track — from exploitation and impact.

Trackcoordinatorcisa_ssvcUS
04

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-114USCWE-200US
05

affected products (13)

Products and version ranges known to be affected.

06

advisories (4)

Vendor and ecosystem advisories describing this.

  • RHSA-2021:2130Red Hat Security Advisory: Windows Container Support for Red Hat OpenShift 2.0.1 security and bug fix update2021-06-23csaf · redhat_csafUS

    The components for Windows Container Support for Red Hat OpenShift 2.0.1 are now available. Red Hat Product Security has rated this update as having a security impact of Moderate. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available for each vulnerability from the CVE link(s) in the References section.

  • WID-SEC-W-2022-0510IBM DB2: Mehrere SchwachstellenDeutsch2022-06-29csaf · cert_bundDE

    Ein entfernter, anonymer, authentisierter oder lokaler Angreifer kann mehrere Schwachstellen in IBM DB2 ausnutzen, um Dateien zu manipulieren, Sicherheitsmaßnahmen zu umgehen, vertrauliche Informationen offenzulegen, einen Denial-of-Service-Zustand auszulösen, willkürlichen Code mit erhöhten Rechten auszuführen, Informationen falsch darzustellen und beliebigen Code auszuführen.

  • GHSA-35c7-w35f-xwghKube-proxy may unintentionally forward traffic2023-10-30ghsa · osvUS

    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.

  • GO-2023-2159Kube-proxy may unintentionally forward traffic in k8s.io/kubernetes2024-08-21vendor · osvUS

    Kube-proxy may unintentionally forward traffic in k8s.io/kubernetes

07

also known as (5)

Other names and identifiers for this entity.

08

sources

Which sources assert this record, and when.

cnnvdenisa_euvdosvcert_bundnvdredhat_csafNVDCVE.orgMITRE
published 2023-10-30modified 2026-06-17
09

references (15)

External citations — patches, advisories, analysis.

scry

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