# CVE-2020-8570: Kubernetes Java client libraries unvalidated path traversal in Copy implementation

> Attackers can overwrite arbitrary files on the host system by exploiting path traversal in the Kubernetes Java client library during file copy operations.

- **Severity:** Critical 9.1 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 21 Jan 2021
- **Updated:** 16 Sep 2024
- **Also known as:** GHSA-cghx-9gcr-r42x

## What is CVE-2020-8570?

CVE-2020-8570 is a critical path traversal vulnerability in Kubernetes Java Client, published on 21 Jan 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Kubernetes Java client libraries in version 10.0.0 and versions prior to 9.0.1 allow writes to paths outside of the current directory when copying multiple files from a remote pod which sends a maliciously crafted archive. This can potentially overwrite any files on the system of the process executing the client code.

Weakness: CWE-22 (Improper Limitation of a Pathname to a Restricted Directory), CWE-23 (Relative Path Traversal)

## Which versions are affected by CVE-2020-8570?

4 open source packages ship an affected version, including io.kubernetes:client-java. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `io.kubernetes:client-java` | Maven | All versions | 9.0.2 |
| `io.kubernetes:client-java` | Maven | All versions | 9.0.2 |
| `io.kubernetes:client-java` | Maven | From 10.0.0 | 10.0.1 |
| `io.kubernetes:client-java` | Maven | From 10.0.0 | 10.0.1 |

Products: Kubernetes Java.

## How do I fix CVE-2020-8570?

Upgrade io.kubernetes:client-java to a fixed version for your release line: 9.0.2 or 10.0.1.

## Is CVE-2020-8570 being exploited?

There is no known exploitation of CVE-2020-8570 in the wild and no public exploit code.

Public exploit code:

- https://github.com/shoucheng3/kubernetes-client__java_CVE-2020-8570_client-java-parent-9_0_2_fixed (github_poc): https://github.com/shoucheng3/kubernetes-client__java_CVE-2020-8570_client-java-parent-9_0_2_fixed

## Other vulnerabilities in Kubernetes Java Client

- [CVE-2021-25738](https://insights.sbomify.com/CVE-2021-25738/): Code exec via yaml parsing (medium 6.7)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-8570 and fix it if it is affected.

What it is: CVE-2020-8570 is a critical path traversal vulnerability in Kubernetes Java Client, published on 21 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-2020-8570 in the wild and no public exploit code.

Affected packages and fixed versions:
- io.kubernetes:client-java (Maven): affected all versions; fixed in 9.0.2
- io.kubernetes:client-java (Maven): affected all versions; fixed in 9.0.2
- io.kubernetes:client-java (Maven): affected from 10.0.0; fixed in 10.0.1
- io.kubernetes:client-java (Maven): affected from 10.0.0; fixed in 10.0.1

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-2020-8570/ (Markdown: https://insights.sbomify.com/CVE-2020-8570/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-8570
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-8570
- OSV: https://osv.dev/vulnerability/CVE-2020-8570

---
From sbomify Insights: https://insights.sbomify.com/CVE-2020-8570/
Summaries are generated and may contain mistakes; the official description above is the record.