CVE-2021-4314
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedIt 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.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidenceJWT token validation can be bypassed in IBM z/OSMF versions 1.16-1.19, allowing attackers to authenticate as any user without knowing the JWT secret. This occurs when APAR PH12143 is not applied, causing the ZAAS client or API ML API to incorrectly trust invalid JWT tokens.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data>= 1.16.0, < 1.19.0CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- Low
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Identify Zowe API ML versionRun 'java -jar api-catalog-services.jar --version' or check the manifest.yaml file in the API ML installation directoryAffected if Version is 1.16.0 or higher but lower than 1.19.0
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Check for APAR PH12143 on z/OSMFQuery IBM System iFix or APAR status for PH12143 on the z/OSMF system that the API ML connects toAffected if APAR PH12143 is not applied to z/OSMF
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Verify JWT token validation is rejecting invalid tokensSend a request with a tampered, expired, or malformed JWT token to a protected API ML endpoint and observe whether authentication is rejectedAffected if Tampered or invalid JWT tokens are accepted and authentication succeeds when it should fail
You are affected if your Zowe API ML version is >= 1.16.0 and < 1.19.0 AND either APAR PH12143 is not applied to z/OSMF OR invalid JWT tokens are incorrectly accepted for authentication.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
dbcve · scoped1.19.0
Apply IBM APAR PH12143 to z/OSMF to fix the JWT validation vulnerability. Verify that JWT authentication properly rejects tampered or invalid tokens after the patch.
Zowe API Mediation Layer 1.19.0 or later
- Back up your current Zowe configuration and data
- Review the Zowe 1.19.0 release notes and upgrade documentation for any pre-upgrade requirements
- Ensure zOSMF has APAR PH12143 applied if possible, or understand the partial mitigation
- Upgrade the Zowe API Mediation Layer to version 1.19.0 or later
- After upgrade, verify JWT authentication is working correctly and test that token validation properly rejects tampered tokens
- Confirm the ZAAS client and API ML API correctly validate JWT tokens
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation4.0 h
- Implementation8.0 h
- Testing4.0 h
- Review / QA2.0 h
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Free · runs locallyCheck whether your project pulls in CVE-2021-4314 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2021-4314 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Version or environment caveats, and links to real fixes
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