# CVE-2020-20741: Auth bypass in n/a

> Remote attackers can bypass authentication on Beckhoff CX9020 devices by exploiting improper connection handling in the CE Remote Display Tool.

- **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:** No
- **Published:** 23 Jul 2021
- **Updated:** 4 Aug 2024
- **Also known as:** GHSA-rprh-9x53-mwjp

## What is CVE-2020-20741?

CVE-2020-20741 is a critical authentication bypass vulnerability in n/a, published on 23 Jul 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Incorrect Access Control in Beckhoff Automation GmbH & Co. KG CX9020 with firmware version CX9020_CB3011_WEC7_HPS_v602_TC31_B4016.6 allows remote attackers to bypass authentication via the "CE Remote Display Tool" as it does not close the incoming connection on the Windows CE side if the credentials are incorrect.

## Which versions are affected by CVE-2020-20741?

It affects 1 product.


Products: Beckhoff Cx9020.

## How do I fix CVE-2020-20741?

No fix has been published for CVE-2020-20741 yet. Limit exposure of the affected software until one is available.

## Is CVE-2020-20741 being exploited?

There is no known exploitation of CVE-2020-20741 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-20741 and fix it if it is affected.

What it is: CVE-2020-20741 is a critical authentication bypass vulnerability in n/a, published on 23 Jul 2021. 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-2020-20741 in the wild and no public exploit code.

Affected product: n/a. 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-2020-20741/ (Markdown: https://insights.sbomify.com/CVE-2020-20741/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-20741
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-20741
- OSV: https://osv.dev/vulnerability/CVE-2020-20741

---
From sbomify Insights: https://insights.sbomify.com/CVE-2020-20741/
Summaries are generated and may contain mistakes; the official description above is the record.