# CVE-2021-21001: WAGO: PFC200 Access to files outside the home directory

> An authorized attacker can access files outside the home directory with higher privileges on WAGO PFC200 controllers via crafted packets.

- **Severity:** Critical 9.1 (`CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 24 May 2021
- **Updated:** 16 Sep 2024
- **Also known as:** GHSA-52pm-rch7-vfc5

## What is CVE-2021-21001?

CVE-2021-21001 is a critical path traversal vulnerability in WAGO Series Ethernet Controller, published on 24 May 2021. An attacker needs administrator access to exploit it, with no action from the victim.

### Official description

On WAGO PFC200 devices in different firmware versions with special crafted packets an authorised attacker with network access to the device can access the file system with higher privileges.

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

## Which versions are affected by CVE-2021-21001?

It affects 27 products.


Products: Wago 750-8202 Firmware, Wago 750-8203 Firmware, Wago 750-8204 Firmware, Wago 750-8206 Firmware, Wago 750-8207 Firmware, Wago 750-8208 Firmware, Wago 750-8210 Firmware, Wago 750-8211 Firmware, Wago 750-8212 Firmware, Wago 750-8213 Firmware, Wago 750-8214 Firmware, Wago 750-8216 Firmware, Wago 750-8217 Firmware, Wago 750-823 Firmware, Wago 750-829 Firmware, Wago 750-831 Firmware, Wago 750-832 Firmware, Wago 750-852 Firmware, Wago 750-862 Firmware, Wago 750-880 Firmware and 7 more.

## How do I fix CVE-2021-21001?

No fix has been published for CVE-2021-21001 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-21001 being exploited?

There is no known exploitation of CVE-2021-21001 in the wild and no public exploit code.

## Other vulnerabilities in WAGO Series Ethernet Controller

- [CVE-2021-21000](https://insights.sbomify.com/CVE-2021-21000/): WAGO: PFC200 Denial of Service due to the number of connections to the runtime (medium 5.3)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-21001 and fix it if it is affected.

What it is: CVE-2021-21001 is a critical path traversal vulnerability in WAGO Series Ethernet Controller, published on 24 May 2021. An attacker needs administrator access to exploit it, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2021-21001 in the wild and no public exploit code.

Affected product: WAGO Series Ethernet Controller. 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-2021-21001/ (Markdown: https://insights.sbomify.com/CVE-2021-21001/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-21001
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-21001
- OSV: https://osv.dev/vulnerability/CVE-2021-21001

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-21001/
Summaries are generated and may contain mistakes; the official description above is the record.