CVE-2020-8552: Kubernetes API server denial of service

Published Feb 4, 2020
·
Updated

A denial of service vulnerability was found in the Kubernetes API server. This flaw allows a remote attacker to send repeated, crafted HTTP requests to exhaust available memory and cause a crash.

Other sources

A flaw was found in the Kubernetes API server that allows for memory exhaustion and subsequent denial of service. A label in a Kubernetes apiserver metric that reflects the client's user agent is included for debugging purposes, but every value added adds a sustained memory overhead as the metric is now tracked. This is particularly dangerous on commonly unauthenticated APIs (selfsubjectaccessreview for example) and can be performed by any authenticated user.

Upstream Fixes:

1.18: https://github.com/kubernetes/kubernetes/pull/87669 1.17: https://github.com/kubernetes/kubernetes/pull/87673 1.16: https://github.com/kubernetes/kubernetes/pull/87681 1.15: https://github.com/kubernetes/kubernetes/pull/87682

— Red Hat

The Kubernetes API server component in Kubernetes versions prior to 1.15.9, 1.16.0-1.16.6, and 1.17.0-1.17.2 has been found to be vulnerable to a denial of service attack via successful API requests.

The Kubernetes API server component in versions prior to 1.15.9, 1.16.0-1.16.6, and 1.17.0-1.17.2 has been found to be vulnerable to a denial of service attack via successful API requests.

Affected Software

30 affected componentsFixes available
go/k8s.io/apiserver>=0.17.0<0.17.3
0.17.3
go/k8s.io/apiserver>=0.16.0<0.16.7
0.16.7
go/k8s.io/apiserver<0.15.10
0.15.10
redhat/atomic-enterprise-service-catalog<1:3.11.219-1.git.1.717017c.el7
1:3.11.219-1.git.1.717017c.el7
redhat/atomic-openshift<0:3.11.219-1.git.0.0c21387.el7
0:3.11.219-1.git.0.0c21387.el7
redhat/atomic-openshift-cluster-autoscaler<0:3.11.219-1.git.1.1ad3e34.el7
0:3.11.219-1.git.1.1ad3e34.el7
redhat/atomic-openshift-descheduler<0:3.11.219-1.git.1.7e5b9ee.el7
0:3.11.219-1.git.1.7e5b9ee.el7
redhat/atomic-openshift-dockerregistry<0:3.11.219-1.git.1.8323991.el7
0:3.11.219-1.git.1.8323991.el7
redhat/atomic-openshift-metrics-server<0:3.11.219-1.git.1.6fe54fb.el7
0:3.11.219-1.git.1.6fe54fb.el7
redhat/atomic-openshift-node-problem-detector<0:3.11.219-1.git.1.5ae8753.el7
0:3.11.219-1.git.1.5ae8753.el7
redhat/atomic-openshift-service-idler<0:3.11.219-1.git.1.958cdae.el7
0:3.11.219-1.git.1.958cdae.el7
redhat/golang-github-openshift-oauth-proxy<0:3.11.219-1.git.1.076ae14.el7
0:3.11.219-1.git.1.076ae14.el7
redhat/golang-github-prometheus-alertmanager<0:3.11.219-1.git.1.9a593f8.el7
0:3.11.219-1.git.1.9a593f8.el7
redhat/golang-github-prometheus-prometheus<0:3.11.219-1.git.1.3f6e657.el7
0:3.11.219-1.git.1.3f6e657.el7
redhat/openshift-ansible<0:3.11.219-1.git.0.8845382.el7
0:3.11.219-1.git.0.8845382.el7
redhat/openshift-enterprise-autoheal<0:3.11.219-1.git.1.c544df9.el7
0:3.11.219-1.git.1.c544df9.el7
redhat/openshift-enterprise-cluster-capacity<0:3.11.219-1.git.1.ca1ee51.el7
0:3.11.219-1.git.1.ca1ee51.el7
redhat/openshift-kuryr<0:3.11.219-1.git.1.717d59f.el7
0:3.11.219-1.git.1.717d59f.el7
redhat/atomic-openshift<0:3.11.248-1.git.0.92ee8ac.el7
0:3.11.248-1.git.0.92ee8ac.el7
redhat/openshift<0:4.2.29-202004110432.git.0.f7d02c8.el8
0:4.2.29-202004110432.git.0.f7d02c8.el8
redhat/openshift<0:4.3.9-202003230116.git.0.ebf9a26.el7
0:4.3.9-202003230116.git.0.ebf9a26.el7
redhat/kube-apiserver<1.17.3
1.17.3
redhat/kube-apiserver<1.16.7
1.16.7
redhat/kube-apiserver<1.15.10
1.15.10
Kubernetes kubernetes<=1.15.9
Kubernetes kubernetes>=1.16.0<=1.16.6
Kubernetes kubernetes>=1.17.0<=1.17.2
Fedoraproject Fedora=32
IBM Watson Studio on Cloud Pak for Data<=4.0
IBM Watson Studio on Cloud Pak for Data<=5.0

Remediation

Recommended actions to resolve this vulnerability, in priority order.

  1. Upgrade

    Upgrade go/k8s.io/apiserver to a version that resolves this vulnerability.

    Fixed in 0.17.3
  2. Upgrade

    Upgrade go/k8s.io/apiserver to a version that resolves this vulnerability.

    Fixed in 0.16.7
  3. Upgrade

    Upgrade go/k8s.io/apiserver to a version that resolves this vulnerability.

    Fixed in 0.15.10
  4. Upgrade

    Upgrade redhat/atomic-enterprise-service-catalog to a version that resolves this vulnerability.

    Fixed in 1:3.11.219-1.git.1.717017c.el7
  5. Upgrade

    Upgrade redhat/atomic-openshift to a version that resolves this vulnerability.

    Fixed in 0:3.11.219-1.git.0.0c21387.el7
  6. Upgrade

    Upgrade redhat/atomic-openshift-cluster-autoscaler to a version that resolves this vulnerability.

    Fixed in 0:3.11.219-1.git.1.1ad3e34.el7
  7. Upgrade

    Upgrade redhat/atomic-openshift-descheduler to a version that resolves this vulnerability.

    Fixed in 0:3.11.219-1.git.1.7e5b9ee.el7
  8. Upgrade

    Upgrade redhat/atomic-openshift-dockerregistry to a version that resolves this vulnerability.

    Fixed in 0:3.11.219-1.git.1.8323991.el7
  9. Upgrade

    Upgrade redhat/atomic-openshift-metrics-server to a version that resolves this vulnerability.

    Fixed in 0:3.11.219-1.git.1.6fe54fb.el7
  10. Upgrade

    Upgrade redhat/atomic-openshift-node-problem-detector to a version that resolves this vulnerability.

    Fixed in 0:3.11.219-1.git.1.5ae8753.el7
  11. Upgrade

    Upgrade redhat/atomic-openshift-service-idler to a version that resolves this vulnerability.

    Fixed in 0:3.11.219-1.git.1.958cdae.el7
  12. Upgrade

    Upgrade redhat/golang-github-openshift-oauth-proxy to a version that resolves this vulnerability.

    Fixed in 0:3.11.219-1.git.1.076ae14.el7
  13. Upgrade

    Upgrade redhat/golang-github-prometheus-alertmanager to a version that resolves this vulnerability.

    Fixed in 0:3.11.219-1.git.1.9a593f8.el7
  14. Upgrade

    Upgrade redhat/golang-github-prometheus-prometheus to a version that resolves this vulnerability.

    Fixed in 0:3.11.219-1.git.1.3f6e657.el7
  15. Upgrade

    Upgrade redhat/openshift-ansible to a version that resolves this vulnerability.

    Fixed in 0:3.11.219-1.git.0.8845382.el7
  16. Upgrade

    Upgrade redhat/openshift-enterprise-autoheal to a version that resolves this vulnerability.

    Fixed in 0:3.11.219-1.git.1.c544df9.el7
  17. Upgrade

    Upgrade redhat/openshift-enterprise-cluster-capacity to a version that resolves this vulnerability.

    Fixed in 0:3.11.219-1.git.1.ca1ee51.el7
  18. Upgrade

    Upgrade redhat/openshift-kuryr to a version that resolves this vulnerability.

    Fixed in 0:3.11.219-1.git.1.717d59f.el7
  19. Upgrade

    Upgrade redhat/atomic-openshift to a version that resolves this vulnerability.

    Fixed in 0:3.11.248-1.git.0.92ee8ac.el7
  20. Upgrade

    Upgrade redhat/openshift to a version that resolves this vulnerability.

    Fixed in 0:4.2.29-202004110432.git.0.f7d02c8.el8
  21. Upgrade

    Upgrade redhat/openshift to a version that resolves this vulnerability.

    Fixed in 0:4.3.9-202003230116.git.0.ebf9a26.el7
  22. Upgrade

    Upgrade redhat/kube-apiserver to a version that resolves this vulnerability.

    Fixed in 1.17.3
  23. Upgrade

    Upgrade redhat/kube-apiserver to a version that resolves this vulnerability.

    Fixed in 1.16.7
  24. Upgrade

    Upgrade redhat/kube-apiserver to a version that resolves this vulnerability.

    Fixed in 1.15.10
  25. Upgrade

    Upgrade Kubernetes (kube-apiserver) to a version that resolves this vulnerability.

    Fixed in 1.15.9
  26. Upgrade

    Upgrade Kubernetes (kube-apiserver) to a version that resolves this vulnerability.

    Fixed in 1.16.7
  27. Upgrade

    Upgrade Kubernetes (kube-apiserver) to a version that resolves this vulnerability.

    Fixed in 1.17.3
  28. Compensating control

    Prevent unauthenticated or unauthorized access to all APIs exposed by the Kubernetes API server (especially commonly unauthenticated endpoints such as selfsubjectaccessreview).

Event History

Feb 4, 2020
Data Sourced
via Red Hat·08:13 AM
DescriptionSeverityAffected Software
Mar 23, 2020
CVE Published
12:00 AM
Mar 27, 2020
CVE Published
via MITRE·02:25 PM
Data Sourced
via MITRE·02:25 PM
DescriptionSeverityWeakness
Data Sourced
via NVD·03:15 PM
RemedyDescriptionSeverityWeaknessAffected Software
Feb 15, 2022
Advisory Published
01:57 AM
Aug 28, 2025
Data Sourced
via IBM·12:00 AM
DescriptionAffected Software

Parent advisories

This vulnerability appears in the following advisories.

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Frequently Asked Questions

1

What is CVE-2020-8552?

CVE-2020-8552 is a vulnerability in the Kubernetes API server component that allows for a denial of service attack via successful API requests.

2

What is the severity of CVE-2020-8552?

The severity of CVE-2020-8552 is medium with a CVSS score of 5.3.

3

Which versions of Kubernetes are affected by CVE-2020-8552?

Kubernetes versions prior to 1.15.9, 1.16.0-1.16.6, and 1.17.0-1.17.2 are affected by CVE-2020-8552.

4

How can I fix CVE-2020-8552?

To fix CVE-2020-8552, ensure that you are using Kubernetes version 1.15.9, 1.16.0-1.16.6, or 1.17.0-1.17.2.

5

Where can I find more information about CVE-2020-8552?

You can find more information about CVE-2020-8552 on the CVE website, NIST's vulnerability database, Kubernetes GitHub issues, Google Groups, and Red Hat Bugzilla and Errata.

Company

Resources

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