# CVE-2021-33542: Phoenix Contact: Automation Worx Software Suite affected by Remote Code Execution (RCE) vulnerability

> Attackers can execute arbitrary code on programming workstations by tricking users into opening manipulated project files, compromising system integrity and availability.

- **Severity:** High 7.8 (`CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 25 Jun 2021
- **Updated:** 17 Sep 2024
- **Also known as:** GHSA-88r6-jjq4-269q

## What is CVE-2021-33542?

CVE-2021-33542 is a high-severity use after free vulnerability in Phoenix Contact Automation Worx Software Suite, published on 25 Jun 2021. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.

### Official description

Phoenix Contact Classic Automation Worx Software Suite in Version 1.87 and below is affected by a remote code execution vulnerability. Manipulated PC Worx or Config+ projects could lead to a remote code execution when unallocated memory is freed because of incompletely initialized data. The attacker needs to get access to an original bus configuration file (*.bcp) to be able to manipulate data inside. After manipulation the attacker needs to exchange the original file by the manipulated one on the application programming workstation. Availability, integrity, or confidentiality of an application programming workstation might be compromised by attacks using these vulnerabilities. Automated systems in operation which were programmed with one of the above-mentioned products are not affected.

Weakness: CWE-824 (Access of Uninitialized Pointer)

## Which versions are affected by CVE-2021-33542?

It affects 3 products.


Products: Phoenixcontact Config\+, Phoenixcontact Pc Worx, Phoenixcontact Pc Worx Express.

## How do I fix CVE-2021-33542?

No fix has been published for CVE-2021-33542 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-33542 being exploited?

There is no known exploitation of CVE-2021-33542 in the wild and no public exploit code.

## Other vulnerabilities in Phoenix Contact Automation Worx Software Suite

- [CVE-2019-16675](https://insights.sbomify.com/CVE-2019-16675/): Memory corruption in n/a (high 7.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-33542 and fix it if it is affected.

What it is: CVE-2021-33542 is a high-severity use after free vulnerability in Phoenix Contact Automation Worx Software Suite, published on 25 Jun 2021. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2021-33542 in the wild and no public exploit code.

Affected product: Phoenix Contact Automation Worx Software Suite. 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-2021-33542/ (Markdown: https://insights.sbomify.com/CVE-2021-33542/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-33542
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-33542
- OSV: https://osv.dev/vulnerability/CVE-2021-33542

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-33542/
Summaries are generated and may contain mistakes; the official description above is the record.