CVE-2021-20238

3.7 LOW 0.8% exploit odds Fix listed

What it is

It was found in OpenShift Container Platform 4 that ignition config, served by the Machine Config Server, can be accessed externally from clusters without authentication. The MCS endpoint (port 22623) provides ignition configuration used for bootstrapping Nodes and can include some sensitive data, e.g. registry pull secrets. There are two scenarios where this data can be accessed. The first is on Baremetal, OpenStack, Ovirt, Vsphere and KubeVirt deployments which do not have a separate internal API endpoint and allow access from outside the cluster to port 22623 from the standard OpenShift API Virtual IP address. The second is on cloud deployments when using unsupported network plugins, which do not create iptables rules that prevent to port 22623. In this scenario, the ignition config is exposed to all pods within the cluster and cannot be accessed externally.

At a glance

Exploitability: Can be exploited over the network without logging in. Limited direct impact.
Exploit odds: 0.8% chance of exploitation in the next 30 days (EPSS).
Fix: A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

2022-04-01 23:15 UTC PublishedDisclosed publicly on CVE.org and NVD
2026-06-17 03:33 UTC Last updatedMost recent change to the record

Why it ranks here

Exploited in the wild: no, CISA does not list it.
Exploit odds: 0.8% in the next 30 days (EPSS).
Severity: 3.7 LOW (CVSS).
Fix: a patch or advisory is linked.

Details

Published: 2022-04-01 23:15 UTC
Last modified: 2026-06-17 03:33 UTC
Exploit probability: 0.8% · EPSS, next 30 days
Weakness: CWE-287 · Improper authentication
Record status: Modified

Affected

Redhat Openshift Container Platform 4.0
Redhat Openshift machine-config-operator ≤ 4.9.0

Attack profile CVSS 3.1 · 3.7

Attack vector: Network
Complexity: High
Privileges needed: None
User interaction: None
Scope: Unchanged
Confidentiality: Low
Integrity: None
Availability: None

Raw vector

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2021-20238.md and follow it. Check whether this project is affected by CVE-2021-20238. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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Fix and advisories

References

NVD record · CVE.org record