CVE-2021-21430

Name: CVE-2021-21430
Creator: NVD / NIST
Published: 2021-05-10T20:15:07.84+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 5.5/10EPSS 0.40%

Last modified Jun 17, 2026

CVE-2021-21430 is a medium-severity vulnerability rated 5.5/10 on the CVSS scale. OpenAPI Generator allows generation of API client libraries (SDK generation), server stubs, documentation and configuration automatically given an OpenAPI Spec. Using `File.createTempFile` in JDK will result in creating and using insecure temporary files that can leave application and system data vulnerable to attacks. EPSS estimates a 0.40% chance of exploitation in the next 30 days.

Description

OpenAPI Generator allows generation of API client libraries (SDK generation), server stubs, documentation and configuration automatically given an OpenAPI Spec. Using `File.createTempFile` in JDK will result in creating and using insecure temporary files that can leave application and system data vulnerable to attacks. Auto-generated code (Java, Scala) that deals with uploading or downloading binary data through API endpoints will create insecure temporary files during the process. Affected generators: `java` (jersey2, okhttp-gson (default library)), `scala-finch`. The issue has been patched with `Files.createTempFile` and released in the v5.1.0 stable version.

Metrics

CVSS 3.1

5.5/10

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

EPSS Probability

0.40%

32.2th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Openapi-Generator	Openapi Generator	< 5.1.1

References

https://github.com/OpenAPITools/openapi-generator/pull/8787Patch, Third Party Advisory
https://github.com/OpenAPITools/openapi-generator/pull/8791Patch, Third Party Advisory
https://github.com/OpenAPITools/openapi-generator/security/advisories/GHSA-cqxr-xf2w-943wExploit, Third Party Advisory
https://github.com/OpenAPITools/openapi-generator/pull/8787Patch, Third Party Advisory
https://github.com/OpenAPITools/openapi-generator/pull/8791Patch, Third Party Advisory
https://github.com/OpenAPITools/openapi-generator/security/advisories/GHSA-cqxr-xf2w-943wExploit, Third Party Advisory

Timeline

Published: May 10, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-21430?

How severe is CVE-2021-21430?

CVE-2021-21430 has a CVSS score of 5.5/10 (MEDIUM severity). The EPSS model estimates a 0.40% probability of exploitation in the next 30 days.

How do I fix CVE-2021-21430?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-21430?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST