# CVE-2021-21243: Pre-Auth Unsafe Deserialization on KubernetesResource

> Unauthenticated attackers can achieve remote code execution via unsafe deserialization in the Kubernetes REST endpoint of the OneDev platform.

- **Severity:** Critical 10.0 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 15 Jan 2021
- **Updated:** 3 Aug 2024
- **Also known as:** GHSA-9mmq-fm8c-q4fv

## What is CVE-2021-21243?

CVE-2021-21243 is a critical unsafe deserialization vulnerability in theonedev onedev, published on 15 Jan 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

OneDev is an all-in-one devops platform. In OneDev before version 4.0.3, a Kubernetes REST endpoint exposes two methods that deserialize untrusted data from the request body. These endpoints do not enforce any authentication or authorization checks. This issue may lead to pre-auth RCE. This issue was fixed in 4.0.3 by not using deserialization at KubernetesResource side.

Weakness: CWE-502 (Deserialization of Untrusted Data), CWE-74 (Improper Neutralization of Special Elements in Output Used by a Downstream Component)

## Which versions are affected by CVE-2021-21243?

It affects 1 product.


Products: Onedev Project Onedev.

## How do I fix CVE-2021-21243?

No fix has been published for CVE-2021-21243 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-21243 being exploited?

There is no known exploitation of CVE-2021-21243 in the wild and no public exploit code.

## Other vulnerabilities in theonedev onedev

- [CVE-2021-21242](https://insights.sbomify.com/CVE-2021-21242/): Pre-Auth Unsafe Deserialization on AttachmentUploadServet (critical 10.0)
- [CVE-2021-21244](https://insights.sbomify.com/CVE-2021-21244/): Pre-Auth SSTI via Bean validation message tampering (critical 10.0)
- [CVE-2021-21245](https://insights.sbomify.com/CVE-2021-21245/): Pre-Auth Arbitrary File Upload (critical 10.0)
- [CVE-2022-39206](https://insights.sbomify.com/CVE-2022-39206/): CI/CD Docker Escape in OneDev (critical 9.9)
- [CVE-2021-21247](https://insights.sbomify.com/CVE-2021-21247/): Post-Auth Unsafe Deserialization on BasePage (AJAX) (critical 9.6)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-21243 and fix it if it is affected.

What it is: CVE-2021-21243 is a critical unsafe deserialization vulnerability in theonedev onedev, published on 15 Jan 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2021-21243 in the wild and no public exploit code.

Affected product: theonedev onedev. No package-level version data is available, so check the vendor advisory linked from the reference page.

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-2021-21243/ (Markdown: https://insights.sbomify.com/CVE-2021-21243/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-21243
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-21243
- OSV: https://osv.dev/vulnerability/CVE-2021-21243

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-21243/
Summaries are generated and may contain mistakes; the official description above is the record.