What’s Vulnerable › Vulnerabilities

CVE-2021-21428: Creation of Temporary File in Directory with Insecure Permissions in the OpenAPI-Generator online generator

• Severity: high (CVSS 7.0 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.4% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2021-05-10 · updated 2026-06-17
• Weakness: CWE-269

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.

Affected products

• OpenAPITools openapi-generator: before 5.1.0 — fixed in 5.1.0

How to fix

Upgrade to a fixed version: OpenAPITools openapi-generator 5.1.0. Check the vendor advisory for mitigations.

References

• https://github.com/OpenAPITools/openapi-generator/pull/8788
• https://github.com/OpenAPITools/openapi-generator/security/advisories/GHSA-23x4-m842-fmwf
• https://github.com/OpenAPITools/openapi-generator/pull/8788
• https://github.com/OpenAPITools/openapi-generator/security/advisories/GHSA-23x4-m842-fmwf

Get alerted when CVE-2021-21428 or the next vulnerability affects your stack