# CVE-2020-36566: Path traversal in github.com/whyrusleeping/tar-utils

> Attackers can write or overwrite files outside the target directory via malicious archives, affecting applications using this Go library.

- **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:** 27 Dec 2022
- **Updated:** 11 Apr 2025
- **Also known as:** GHSA-jpf8-h7h7-3ppm, GO-2021-0106

## What is CVE-2020-36566?

CVE-2020-36566 is a critical path traversal vulnerability in github.com/whyrusleeping/tar-utils, published on 27 Dec 2022. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Due to improper path sanitization, archives containing relative file paths can cause files to be written (or overwritten) outside of the target directory.

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

## Which versions are affected by CVE-2020-36566?

3 open source packages ship an affected version, including github.com/whyrusleeping/tar-utils. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `github.com/whyrusleeping/tar-utils` | Go | All versions | 0.0.0-20201201191210-20a61371de5b |
| `github.com/whyrusleeping/tar-utils` | Go | All versions | 0.0.0-20201201191210-20a61371de5b |
| `github.com/whyrusleeping/tar-utils` | Go | All versions | 0.0.0-20201201191210-20a61371de5b |

Products: Tar-Utils Project Tar-Utils.

## How do I fix CVE-2020-36566?

Upgrade github.com/whyrusleeping/tar-utils to 0.0.0-20201201191210-20a61371de5b or later.

## Is CVE-2020-36566 being exploited?

There is no known exploitation of CVE-2020-36566 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-36566 and fix it if it is affected.

What it is: CVE-2020-36566 is a critical path traversal vulnerability in github.com/whyrusleeping/tar-utils, published on 27 Dec 2022. 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-2020-36566 in the wild and no public exploit code.

Affected packages and fixed versions:
- github.com/whyrusleeping/tar-utils (Go): affected all versions; fixed in 0.0.0-20201201191210-20a61371de5b
- github.com/whyrusleeping/tar-utils (Go): affected all versions; fixed in 0.0.0-20201201191210-20a61371de5b
- github.com/whyrusleeping/tar-utils (Go): affected all versions; fixed in 0.0.0-20201201191210-20a61371de5b

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-2020-36566/ (Markdown: https://insights.sbomify.com/CVE-2020-36566/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-36566
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-36566
- OSV: https://osv.dev/vulnerability/CVE-2020-36566

---
From sbomify Insights: https://insights.sbomify.com/CVE-2020-36566/
Summaries are generated and may contain mistakes; the official description above is the record.