CVE-2021-20238 Missing authorization in openshift/machine-config-operator
Attackers can access sensitive ignition configuration data, including registry secrets, from the Machine Config Server without authentication in specific deployment scenarios.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2021-20238?
CVE-2021-20238 is a low-severity missing authorization vulnerability in Redhat Openshift Container Platform, published on 1 Apr 2022. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
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.
Which versions are affected by CVE-2021-20238?
It affects 2 products.
Products include Redhat Openshift Container Platform, Redhat Openshift Machine-Config-Operator.
How do I fix CVE-2021-20238?
No fix has been published for CVE-2021-20238 yet. Limit exposure of the affected software until one is available.
Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.
Is CVE-2021-20238 being exploited?
There is no known exploitation of CVE-2021-20238 in the wild and no public exploit code.
Other vulnerabilities in Redhat Openshift Container Platform
- CVE-2020-27836 Missing authorization in cluster-ingress-operator
- CVE-2018-1085 Misconfiguration in openshift-ansible
- CVE-2026-54099 Privilege escalation in Red Hat OpenShift Container Platform 4
- CVE-2026-1784 Ose-cluster-ingress-operator: remote code execution through haproxy configuration injection
- CVE-2021-20182 Privilege escalation in openshift