What is CVE-2021-3636?

CVE-2021-3636 is a medium-severity vulnerability in Red Hat Openshift, classified under Improper Certificate Validation. CVSS score: 4.6/10. Published 2021-07-30.

How severe is CVE-2021-3636?

Medium severity. CVSS v3 base score is 4.6 out of 10.

Is CVE-2021-3636 known to be exploited?

1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.

Auth bypass in Red Hat Openshift

CVE-2021-3636

It was found in OpenShift, before version 4.8, that the generated certificate for the in-cluster Service CA, incorrectly included additional certificates. The Service CA is automatically mounted into all pods, allowing them to safely connect to trusted in-cluster services that present certificates signed by the trusted Service CA. The incorrect inclusion of additional CAs in this certificate would allow an attacker that compromises any of the additional CAs to masquerade as a trusted in-cluster service.

Vulnerability class: Improper Certificate Validation

EPSS: 0.003 (20.6th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 4.6 (Medium). Vector: CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N.

Affected products

Redhat Openshift
N/a Openshift — versions openshift 4.8

Weakness classification (CWE)

Public proof-of-concept exploits

ARPSyndicate/cvemon

References

secalert@redhat.com (Exploit, Patch, Third Party Advisory, x_refsource_MISC, Issue Tracking)

Frequently asked questions

What is CVE-2021-3636?: CVE-2021-3636 is a medium-severity vulnerability in Red Hat Openshift, classified under Improper Certificate Validation. CVSS score: 4.6/10. Published 2021-07-30.
How severe is CVE-2021-3636?: Medium severity. CVSS v3 base score is 4.6 out of 10.
Is CVE-2021-3636 known to be exploited?: 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.