# CVE-2021-4314: Auth bypass in Zowe

> Attackers can bypass JWT authentication to impersonate any user if a specific IBM z/OS APAR is missing, leading to unauthorized access and privilege escalation.

- **Severity:** Medium 5.3 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 18 Jan 2023
- **Updated:** 3 Apr 2025
- **Also known as:** GHSA-jrmv-h6h9-gcm3

## What is CVE-2021-4314?

CVE-2021-4314 is a medium-severity authentication bypass vulnerability in Open Mainframe Project Zowe, published on 18 Jan 2023. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

It is possible to manipulate the JWT token without the knowledge of the JWT secret and authenticate without valid JWT token as any user. This is happening only in the situation when zOSMF doesn’t have the APAR PH12143 applied. This issue affects: 1.16 versions to 1.19. What happens is that the services using the ZAAS client or the API ML API to query will be deceived into believing the information in the JWT token is valid when it isn’t. It’s possible to use this to persuade the southbound service that different user is authenticated.

Weakness: CWE-287 (Improper Authentication), CWE-269 (Improper Privilege Management)

## Which versions are affected by CVE-2021-4314?

It affects 1 product.


Products: Linuxfoundation Zowe Api Mediation Layer.

## How do I fix CVE-2021-4314?

No fix has been published for CVE-2021-4314 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-4314 being exploited?

There is no known exploitation of CVE-2021-4314 in the wild and no public exploit code.

## Other vulnerabilities in Open Mainframe Project Zowe

- [CVE-2024-9798](https://insights.sbomify.com/CVE-2024-9798/): Health endpoint offers list of onboarded services to unauthenticated users (medium 5.3)
- [CVE-2024-9802](https://insights.sbomify.com/CVE-2024-9802/): Conformance validation endpoint discloses detail about service to unauthenticated users (medium 5.3)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-4314 and fix it if it is affected.

What it is: CVE-2021-4314 is a medium-severity authentication bypass vulnerability in Open Mainframe Project Zowe, published on 18 Jan 2023. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2021-4314 in the wild and no public exploit code.

Affected product: Open Mainframe Project Zowe. 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-2021-4314/ (Markdown: https://insights.sbomify.com/CVE-2021-4314/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-4314
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-4314
- OSV: https://osv.dev/vulnerability/CVE-2021-4314

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-4314/
Summaries are generated and may contain mistakes; the official description above is the record.