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Fencer Vulns
medium 6.3

CVE-2020-8554 json

Kubernetes man in the middle using LoadBalancer or ExternalIPs

published 2021-01-21 5 y ago modified 2026-09-10 1 mo ago also GHSA-j9wf-vvm6-4r9w , EUVD-2022-1072

cvss
6.3
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
8.7%
EPSS 8.7% chance of exploitation in 30 days, percentile 95%
public exploits
0
none known

Summary

Kubernetes API server in all versions allow an attacker who is able to create a ClusterIP service and set the spec.externalIPs field, to intercept traffic to that IP address. Additionally, an attacker who is able to patch the status (which is considered a privileged operation and should not typically be granted to users) of a LoadBalancer service can set the status.loadBalancer.ingress.ip to similar effect.

Patch / fix

  • kubernetes Debian 14, Debian 13 1.31.4+ds-1

debian advisories DEBIAN-CVE-2020-8554

  • prometheus openshift 3.11 3.11.374-1.git.5026.29379c4.el7
  • python-urllib3 openshift 3.11 1.26.2-1.el7
  • python2-urllib3 openshift 3.11 1.26.2-1.el7
  • atomic-openshift openshift 3.11 3.11.374-1.git.0.ebd3ee9.el7
  • atomic-openshift-pod openshift 3.11 3.11.374-1.git.0.ebd3ee9.el7
  • atomic-openshift-node openshift 3.11 3.11.374-1.git.0.ebd3ee9.el7
  • atomic-openshift-tests openshift 3.11 3.11.374-1.git.0.ebd3ee9.el7
  • atomic-openshift-master openshift 3.11 3.11.374-1.git.0.ebd3ee9.el7

red hat advisories RHSA-2021:0079

  • python-kubernetes CBL-Mariner 2.0, Azure Linux 3.0 21.7.0-1
  • kubernetes CBL-Mariner 2.0 1.28.3-1
  • kubernetes Azure Linux 3.0 1.28.3-2

azure linux advisories AZL-31696AZL-31731AZL-34893AZL-35135

Azure Linux vulnerability data, Copyright (c) Microsoft Corporation, from https://github.com/microsoft/AzureLinuxVulnerabilityData via OSV, under the MIT licence; changed: normalised to fixed package versions per release. MIT

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2020-8554 updated cvss 6.3

kubernetes: MITM using LoadBalancer or ExternalIPs

  • Red Hat OpenShift Container Platform 3.11 atomic-openshift 3.11.374-1.git.0.ebd3ee9.el7, atomic-openshift-pod 3.11.374-1.git.0.ebd3ee9.el7, atomic-openshift-node 3.11.374-1.git.0.ebd3ee9.el7, atomic-openshift-tests 3.11.374-1.git.0.ebd3ee9.el7, atomic-openshift-master 3.11.374-1.git.0.ebd3ee9.el7, atomic-openshift-clients 3.11.374-1.git.0.ebd3ee9.el7, +7 more
    fixed: vendor fix RHSA-2021:0079
  • Red Hat OpenShift Container Platform 3.11 python-urllib3 1.26.2-1.el7, python2-urllib3 1.26.2-1.el7, prometheus 3.11.374-1.git.5026.29379c4.el7, openshift-ansible 3.11.374-1.git.0.92f5956.el7, openshift-kuryr 3.11.374-1.git.1478.ef11824.el7, openshift-ansible-test 3.11.374-1.git.0.92f5956.el7, +23 more Red Hat OpenShift Container Platform 4 openshift, openshift-clients, openshift-kubelet, openshift-hyperkube, openshift-kube-apiserver, openshift-kube-scheduler, +2 more Red Hat Storage 3 heketi, heketi-client, python-heketi
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

8.72% chance of exploitation in the next 30 days, higher than 95% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/kubernetes/kubernetes/issues/97076 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 6.3 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L
NVD 3.1 5.0 CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:L
NVD 2.0 6.0 AV:N/AC:M/Au:S/C:P/I:P/A:P
GitHub 3.1 5.0 CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:L

Affected packages

ecosystem package affected fixed in
go k8s.io/kubernetes
<=1.22.0
 no fix listed

Affected products

  • Kubernetes Kubernetes

Classification

Weakness
Technology feeds

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.