Read the docs
TI-2021-02581 Aliases CVE-2021-3636GHSA-6fcp-x27g-fqqw

Improper certificate validation in openshift

Priority LOW 21CWE-295Published · Updated

Key facts

Attack vector
Adjacent network
Privileges required
Low
User interaction
None
Attack complexity
Low
Impact type
Spoofing, Security bypass
Confidentiality · integrity · availability
Low · Low · None
Fix status
Partial Red Hat: 1 fixed, 1 without a fix

Attack profile from CVSS 3.1 · NVD. Fix status from CNA and Red Hat. Impact type from CWE-295 and CWE-287.

Summary

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.

Why it matters now

EPSS 0.00284 21st percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix Partial Red Hat: 1 advisoryRed Hat: 1 fixed, 1 without a fix

SSVC decision points

Not available: CISA has not published SSVC decision points for this record.

Affected products

VendorProductAffected versionsFixed inStatusSource
—openshiftopenshift 4.8—No fix listedCNA
  • openshift Vendor— Affected openshift 4.8 Fixed in — No fix listed CNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:redhat:openshift:*:*:*:*:*:*:*:*before 4.8VulnerableRed Hat
  • cpe:2.3:a:redhat:openshift:*:*:*:*:*:*:*:* Versions before 4.8 Vulnerable ·Red Hat

Remediation

Red Hat 1 advisory

  • RHSA-2021:2437 Released 2021-07-27 · Red Hat rating Moderate
    OpenShift Container Platform 4.8.2 packages and security update
    • Red Hat OpenShift Container Platform 4.8 afterburn-5.0.0-1.rhaos4.8.el8, atomic-openshift-service-idler-4.8.0-202106281541.p0.git.39cfc66.assembly.stream.el8, butane-0.12.1-1.rhaos4.8.el8 +47

Vendor assessments

Red Hat

Red Hat rating: Moderate. Red Hat's page for this CVE →

ProductStatusPlan or fix
Red Hat OpenShift Container Platform 3.11AffectedNo fix planned: Out of support scope
Red Hat OpenShift Container Platform 4.8Fixed RHSA-2021:2437
Not affected: 1 product
  • Red Hat OpenShift Container Platform 4.8

Timeline

  1. 2026-10-02 Threatist record created from CVE-2021-3636
  2. 2026-10-03 Alias added: GHSA-6fcp-x27g-fqqw

References

Exploit 1

  • TI-2023-23979 The HTTP/2 protocol allows a denial of service (server resource consumption) because… KEVCVSS 3.1HIGH 7.5
  • TI-2015-04472 The Fingerprints pages in Jenkins before 1.638 and LTS before 1.625.2 might allow remote… KEVCVSS 3.1HIGH 7.5
  • TI-2015-06239 Red Hat JBoss A-MQ 6.x; BPM Suite (BPMS) 6.x; BRMS 6.x and 5.x; Data Grid (JDG) 6.x; Data… CVSS 3.0CRITICAL 9.8
  • TI-2019-04061 runc through 1.0-rc6, as used in Docker before 18.09.2 and other products, allows… CVSS 3.1HIGH 8.6
  • TI-2016-00709 Multiple unspecified API endpoints in Jenkins before 1.650 and LTS before 1.642.2 allow… CVSS 3.0HIGH 8.8
  • TI-2024-11209 Rsync: info leak via uninitialized stack contents CVSS 3.1HIGH 7.5
See all 145 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences