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Fencer Vulns
high 8.1

CVE-2021-20198 json

A flaw was found in the OpenShift Installer before version v0.9.0-master.0.20210125200451-95101da940b0.

published 2021-02-23 5 y ago modified 2026-06-17 4 mo ago also EUVD-2021-7644

cvss
8.1
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
1.8%
EPSS 1.8% chance of exploitation in 30 days, percentile 79%
public exploits
0
none known

Summary

A flaw was found in the OpenShift Installer before version v0.9.0-master.0.20210125200451-95101da940b0. During installation of OpenShift Container Platform 4 clusters, bootstrap nodes are provisioned with anonymous authentication enabled on kubelet port 10250. A remote attacker able to reach this port during installation can make unauthenticated `/exec` requests to execute arbitrary commands within running containers. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability.

Patch / fix

  • redhat openshift_installer 0.9.0-master.0.20210125200451-95101da940b0

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-2021-20198 updated cvss 8.1

openshift/installer: Bootstrap nodes allow anonymous authentication on kubelet port 10250

  • Red Hat OpenShift Container Platform 4.5 openshift4/ose-installer v4.5.0-202101301520.p0
    fixed: vendor fix RHSA-2021:0313
  • Red Hat OpenShift Container Platform 4.6 openshift4/ose-installer v4.6.0-202101300140.p0
    fixed: vendor fix RHSA-2021:0308
  • Red Hat OpenShift Container Platform 3.11 atomic-openshift, atomic-openshift-pod, atomic-openshift-node, atomic-openshift-tests, atomic-openshift-master, atomic-openshift-clients, +7 more Red Hat OpenShift Container Platform 4.5 openshift4/ose-cli v4.5.0-202101300210.p0, openshift4/ose-pod v4.5.0-202101300210.p0, openshift4/ose-etcd v4.5.0-202101300210.p0, openshift4/ose-tests v4.5.0-202101300210.p0, openshift4/ose-console v4.5.0-202101300210.p0, openshift4/ose-coredns v4.5.0-202101300210.p0, +75 more Red Hat OpenShift Container Platform 4.6 openshift4/ose-cli v4.6.0-202101301510.p0, openshift4/ose-pod v4.6.0-202101300140.p0, openshift4/ose-etcd v4.6.0-202101300140.p0, openshift4/ose-tests v4.6.0-202101301510.p0, openshift4/ose-console v4.6.0-202101300140.p0, openshift4/ose-coredns v4.6.0-202101300140.p0, +119 more
    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

1.83% chance of exploitation in the next 30 days, higher than 79% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
NVD 3.1 8.1 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD 2.0 6.8 AV:N/AC:M/Au:N/C:P/I:P/A:P

Affected products

  • n/a openshift/installer

Classification

Weakness
  • CWE-306 Missing Authentication for Critical Functionality

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.