# CVE-2021-39143: Path Traversal in spinnaker

> Attackers can exploit path traversal in TAR file extraction during AppEngine deployments to overwrite system files, potentially enabling man-in-the-middle attacks.

- **Severity:** Medium 6.6 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 4 Jan 2022
- **Updated:** 22 Apr 2025

## What is CVE-2021-39143?

CVE-2021-39143 is a medium-severity path traversal vulnerability in spinnaker, published on 4 Jan 2022. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

Spinnaker is an open source, multi-cloud continuous delivery platform. A path traversal vulnerability was discovered in uses of TAR files by AppEngine for deployments. This uses a utility to extract files locally for deployment without validating the paths in that deployment don't override system files. This would allow an attacker to override files on the container, POTENTIALLY introducing a MITM type attack vector by replacing libraries or injecting wrapper files. Users are advised to update as soon as possible. For users unable to update disable Google AppEngine deployments and/or disable artifacts that provide TARs.

Weakness: CWE-22 (Improper Limitation of a Pathname to a Restricted Directory)

## Which versions are affected by CVE-2021-39143?

It affects 1 product.


Products: Linuxfoundation Spinnaker.

## How do I fix CVE-2021-39143?

No fix has been published for CVE-2021-39143 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-39143 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2021-39143 exists.

## Other vulnerabilities in spinnaker

- [CVE-2026-32604](https://insights.sbomify.com/CVE-2026-32604/): Spinnaker: RCE when using gitrepo artifact types due to improper sanitization of user input on branch and paths (critical 10.0)
- [CVE-2026-32613](https://insights.sbomify.com/CVE-2026-32613/): Spinnaker vulnerable to RCE via expression parsing due to unrestricted context handling (critical 10.0)
- [CVE-2021-43832](https://insights.sbomify.com/CVE-2021-43832/): Improper Access Control in spinnaker (critical 10.0)
- [CVE-2026-44795](https://insights.sbomify.com/CVE-2026-44795/): Spinnaker: Non-safe yaml deserialization allowing RCE when using specific types (high 8.8)
- [CVE-2020-9301](https://insights.sbomify.com/CVE-2020-9301/): Code injection in Netflix Spinnaker (high 8.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-39143 and fix it if it is affected.

What it is: CVE-2021-39143 is a medium-severity path traversal vulnerability in spinnaker, published on 4 Jan 2022. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2021-39143 exists.

Affected product: spinnaker. 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-2021-39143/ (Markdown: https://insights.sbomify.com/CVE-2021-39143/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-39143
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-39143
- OSV: https://osv.dev/vulnerability/CVE-2021-39143

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-39143/
Summaries are generated and may contain mistakes; the official description above is the record.