# CVE-2021-3636: Security feature bypass in openshift

> Attackers compromising additional CAs can masquerade as trusted in-cluster services due to incorrect Service CA certificate generation in OpenShift.

- **Severity:** Medium 4.6 (`CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 30 Jul 2021
- **Updated:** 3 Aug 2024
- **Also known as:** GHSA-6fcp-x27g-fqqw

## What is CVE-2021-3636?

CVE-2021-3636 is a medium-severity vulnerability in Redhat Openshift, published on 30 Jul 2021. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

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.

Weakness: CWE-287 (Improper Authentication), CWE-295 (Improper Certificate Validation)

## Which versions are affected by CVE-2021-3636?

It affects 1 product.


Products: Redhat Openshift.

## How do I fix CVE-2021-3636?

Upgrade to a fixed version.

## Is CVE-2021-3636 being exploited?

There is no known exploitation of CVE-2021-3636 in the wild and no public exploit code.

## Other vulnerabilities in Redhat Openshift

- [CVE-2014-3496](https://insights.sbomify.com/CVE-2014-3496/): Command injection in n/a (critical 10.0)
- [CVE-2014-0234](https://insights.sbomify.com/CVE-2014-0234/): Hardcoded credentials in Red Hat OpenShift Enterprise (critical 9.8)
- [CVE-2013-2060](https://insights.sbomify.com/CVE-2013-2060/): Command injection in OpenShift Origin (critical 9.8)
- [CVE-2013-4561](https://insights.sbomify.com/CVE-2013-4561/): Path traversal in openshift-origin-msg-node-mcollective (critical 9.1)
- [CVE-2014-0163](https://insights.sbomify.com/CVE-2014-0163/): Command injection in Openshift (high 8.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-3636 and fix it if it is affected.

What it is: CVE-2021-3636 is a medium-severity vulnerability in Redhat Openshift, published on 30 Jul 2021. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2021-3636 in the wild and no public exploit code.

Affected product: Redhat Openshift. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2021-3636/ (Markdown: https://insights.sbomify.com/CVE-2021-3636/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-3636
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-3636
- OSV: https://osv.dev/vulnerability/CVE-2021-3636

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-3636/
Summaries are generated and may contain mistakes; the official description above is the record.