Creation of Temporary File in Directory with Insecure Permissions in auto-generated Java, Scala code

Vulnerability 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.

References

• https://github.com/OpenAPITools/openapi-generator/security/advisories/GHSA-cqxr-xf2w-943w
• https://github.com/OpenAPITools/openapi-generator/pull/8791
• https://github.com/OpenAPITools/openapi-generator/pull/8787