# CVE-2020-21055: Path traversal in n/a

> Malicious users can rename arbitrary system files via directory traversal in FusionPBX file rename functionality.

- **Severity:** Medium 6.5 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 20 May 2021
- **Updated:** 4 Aug 2024
- **Also known as:** GHSA-r3xv-f88g-47pw

## What is CVE-2020-21055?

CVE-2020-21055 is a medium-severity path traversal vulnerability in Fusionpbx Fusionpbx, published on 20 May 2021. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

A Directory Traversal vulnerability exists in FusionPBX 4.5.7 allows malicoius users to rename any file of the system.via the (1) folder, (2) filename, and (3) newfilename variables in app\edit\filerename.php.

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

## Which versions are affected by CVE-2020-21055?

It affects 1 product.


Products: Fusionpbx Fusionpbx.

## How do I fix CVE-2020-21055?

No fix has been published for CVE-2020-21055 yet. Limit exposure of the affected software until one is available.

## Is CVE-2020-21055 being exploited?

There is no known exploitation of CVE-2020-21055 in the wild and no public exploit code.

## Other vulnerabilities in Fusionpbx Fusionpbx

- [CVE-2022-35153](https://insights.sbomify.com/CVE-2022-35153/): Command injection in n/a (critical 9.8)
- [CVE-2022-28055](https://insights.sbomify.com/CVE-2022-28055/): Command injection in n/a (critical 9.8)
- [CVE-2021-43404](https://insights.sbomify.com/CVE-2021-43404/): Path traversal in n/a (high 8.8)
- [CVE-2021-43405](https://insights.sbomify.com/CVE-2021-43405/): Command injection in n/a (high 8.8)
- [CVE-2021-43406](https://insights.sbomify.com/CVE-2021-43406/): Other in n/a (high 8.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-21055 and fix it if it is affected.

What it is: CVE-2020-21055 is a medium-severity path traversal vulnerability in Fusionpbx Fusionpbx, published on 20 May 2021. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2020-21055 in the wild and no public exploit code.

Affected product: Fusionpbx Fusionpbx. 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-2020-21055/ (Markdown: https://insights.sbomify.com/CVE-2020-21055/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-21055
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-21055
- OSV: https://osv.dev/vulnerability/CVE-2020-21055

---
From sbomify Insights: https://insights.sbomify.com/CVE-2020-21055/
Summaries are generated and may contain mistakes; the official description above is the record.