How severe is CVE-2021-20198?

CVE-2021-20198 has a CVSS 3.x base score of 8.1, rated high severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2021-20198 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (76th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-20198?

CVE-2021-20198 affects Redhat Openshift Installer. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-20198?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2021-20198 published?

CVE-2021-20198 was published on 2021-02-23 and last updated on 2026-06-17.

CVE-2021-20198

CVE-2021-20198 is a high-severity vulnerability in Redhat Openshift Installer with a CVSS 3.x base score of 8.1. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-306.

Key facts

Severity: High (CVSS 3.x base score 8.1)
CVSS v2: 6.8
EPSS exploit prediction: 2% (76th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-306
Affected product: Redhat Openshift Installer
Published: 2021-02-23
Last modified: 2026-06-17

Description

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.

Frequently asked questions

What is CVE-2021-20198?: 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.
How severe is CVE-2021-20198?: CVE-2021-20198 has a CVSS 3.x base score of 8.1, rated high severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2021-20198 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (76th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-20198?: CVE-2021-20198 affects Redhat Openshift Installer. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-20198?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2021-20198 published?: CVE-2021-20198 was published on 2021-02-23 and last updated on 2026-06-17.

References

https://bugzilla.redhat.com/show_bug.cgi?id=1920764

Affected products (1)

cpe:2.3:a:redhat:openshift_installer:*:*:*:*:*:*:*:*

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