CVE-2021-21428

Name: CVE-2021-21428
Creator: NVD / NIST
Published: 2021-05-10T19:15:08.06+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 7/10EPSS 0.35%

Last modified Jun 17, 2026

CVE-2021-21428 is a high-severity vulnerability rated 7/10 on the CVSS scale. Openapi generator is a java tool which allows generation of API client libraries (SDK generation), server stubs, documentation and configuration automatically given an OpenAPI Spec. openapi-generator-online creates insecure temporary folders with File.createTempFile during the code generation process. EPSS estimates a 0.35% chance of exploitation in the next 30 days.

Description

Openapi generator is a java tool which allows generation of API client libraries (SDK generation), server stubs, documentation and configuration automatically given an OpenAPI Spec. openapi-generator-online creates insecure temporary folders with File.createTempFile during the code generation process. The insecure temporary folders store the auto-generated files which can be read and appended to by any users on the system. The issue has been patched with `Files.createTempFile` and released in the v5.1.0 stable version.

Metrics

CVSS 3.1

7/10

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

EPSS Probability

0.35%

27.0th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Openapi-Generator	Openapi Generator	< 5.1.0

References

https://github.com/OpenAPITools/openapi-generator/pull/8788Patch, Third Party Advisory
https://github.com/OpenAPITools/openapi-generator/security/advisories/GHSA-23x4-m842-fmwfExploit, Third Party Advisory
https://github.com/OpenAPITools/openapi-generator/pull/8788Patch, Third Party Advisory
https://github.com/OpenAPITools/openapi-generator/security/advisories/GHSA-23x4-m842-fmwfExploit, Third Party Advisory

Timeline

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

Frequently Asked Questions

What is CVE-2021-21428?

How severe is CVE-2021-21428?

CVE-2021-21428 has a CVSS score of 7/10 (HIGH severity). The EPSS model estimates a 0.35% probability of exploitation in the next 30 days.

How do I fix CVE-2021-21428?

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-2021-21428?

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

Scan your code now

Source: NVD / NIST