# CVE-2021-43421: elFinder Unrestricted File Upload vulnerability

> Remote attackers can upload arbitrary files to execute PHP code in elFinder file manager libraries.

- **Severity:** Critical 9.8 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/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:** 7 Apr 2022
- **Updated:** 4 Aug 2024
- **Also known as:** GHSA-x4jx-hjwf-gc99

## What is CVE-2021-43421?

CVE-2021-43421 is a critical vulnerability in n/a, published on 7 Apr 2022. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A File Upload vulnerability exists in Studio-42 elFinder 2.0.4 to 2.1.59 via connector.minimal.php, which allows a remote malicious user to upload arbitrary files and execute PHP code.

Weakness: CWE-434 (Unrestricted Upload of File with Dangerous Type)

## Which versions are affected by CVE-2021-43421?

2 open source packages ship an affected version, including studio-42/elfinder. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `studio-42/elfinder` | Packagist | From 2.0.4 | 2.1.60 |
| `studio-42/elfinder` | Packagist | From 2.0.4 | 2.1.60 |

Products: Std42 Elfinder.

## How do I fix CVE-2021-43421?

Upgrade studio-42/elfinder to 2.1.60 or later.

## Is CVE-2021-43421 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2021-43421 exists.

Public exploit code:

- Studio-42 elFinder <2.1.60 - Arbitrary File Upload (nuclei): http/cves/2021/CVE-2021-43421.yaml

## Other vulnerabilities in n/a

- [CVE-2023-52044](https://insights.sbomify.com/CVE-2023-52044/): File upload in n/a (critical 9.8)
- [CVE-2024-38909](https://insights.sbomify.com/CVE-2024-38909/): Studio 42 elFinder vulnerable to Incorrect Access Control (critical 9.8)
- [CVE-2022-27115](https://insights.sbomify.com/CVE-2022-27115/): RCE in Studio-42 elFinder on Windows before 2.1.61 (critical 9.8)
- [CVE-2021-32682](https://insights.sbomify.com/CVE-2021-32682/): Multiple vulnerabilities leading to RCE (critical 9.8)
- [CVE-2019-9194](https://insights.sbomify.com/CVE-2019-9194/): elFinder command injection vulnerability in the PHP connector (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-43421 and fix it if it is affected.

What it is: CVE-2021-43421 is a critical vulnerability in n/a, published on 7 Apr 2022. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2021-43421 exists.

Affected packages and fixed versions:
- studio-42/elfinder (Packagist): affected from 2.0.4; fixed in 2.1.60
- studio-42/elfinder (Packagist): affected from 2.0.4; fixed in 2.1.60

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-2021-43421/ (Markdown: https://insights.sbomify.com/CVE-2021-43421/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-43421
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-43421
- OSV: https://osv.dev/vulnerability/CVE-2021-43421

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-43421/
Summaries are generated and may contain mistakes; the official description above is the record.