# CVE-2021-21429: Creation of Temporary File in Directory with Insecure Permissions in the OpenAPI Generator Maven plugin

> Attackers can read or modify insecure temporary files created by the OpenAPI Generator Maven plugin, potentially exposing sensitive data or altering code generation.

- **Severity:** Medium 4.0 (`CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 27 Apr 2021
- **Updated:** 3 Aug 2024
- **Also known as:** GHSA-867q-77cc-98mv

## What is CVE-2021-21429?

CVE-2021-21429 is a medium-severity vulnerability in OpenAPITools openapi-generator, published on 27 Apr 2021. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

OpenAPI Generator allows generation of API client libraries, 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. OpenAPI Generator maven plug-in creates insecure temporary files during the process. The issue has been patched with `Files.createTempFile` and released in the v5.1.0 stable version.

Weakness: CWE-552 (Files or Directories Accessible to External Parties)

## Which versions are affected by CVE-2021-21429?

2 open source packages ship an affected version, including org.openapitools:openapi-generator-maven-plugin. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `org.openapitools:openapi-generator-maven-plugin` | Maven | All versions | 5.1.0 |
| `org.openapitools:openapi-generator-maven-plugin` | Maven | All versions | 5.1.0 |

Products: Openapi-Generator Openapi Generator.

## How do I fix CVE-2021-21429?

Upgrade org.openapitools:openapi-generator-maven-plugin to 5.1.0 or later.

## Is CVE-2021-21429 being exploited?

There is no known exploitation of CVE-2021-21429 in the wild and no public exploit code.

## Other vulnerabilities in OpenAPITools openapi-generator

- [CVE-2021-21428](https://insights.sbomify.com/CVE-2021-21428/): Creation of Temporary File in Directory with Insecure Permissions in the OpenAPI-Generator online generator (critical 9.3)
- [CVE-2023-27162](https://insights.sbomify.com/CVE-2023-27162/): OpenAPI Generator vulnerable to Server-Side Request Forgery (critical 9.1)
- [CVE-2019-11405](https://insights.sbomify.com/CVE-2019-11405/): OpenAPI Tools OpenAPI Generator uses HTTP in various files (high 8.1)
- [CVE-2021-21430](https://insights.sbomify.com/CVE-2021-21430/): Creation of Temporary File in Directory with Insecure Permissions in auto-generated Java, Scala code (medium 6.2)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-21429 and fix it if it is affected.

What it is: CVE-2021-21429 is a medium-severity vulnerability in OpenAPITools openapi-generator, published on 27 Apr 2021. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2021-21429 in the wild and no public exploit code.

Affected packages and fixed versions:
- org.openapitools:openapi-generator-maven-plugin (Maven): affected all versions; fixed in 5.1.0
- org.openapitools:openapi-generator-maven-plugin (Maven): affected all versions; fixed in 5.1.0

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2021-21429/ (Markdown: https://insights.sbomify.com/CVE-2021-21429/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-21429
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-21429
- OSV: https://osv.dev/vulnerability/CVE-2021-21429

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-21429/
Summaries are generated and may contain mistakes; the official description above is the record.