# CVE-2021-29240: Code injection in n/a

> Attackers can install malicious CODESYS packages due to missing validity checks, leading to arbitrary code execution on the development system.

- **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:** 4 May 2021
- **Updated:** 3 Aug 2024
- **Also known as:** GHSA-hp56-5pmq-v75c

## What is CVE-2021-29240?

CVE-2021-29240 is a high-severity code injection vulnerability in n/a, published on 4 May 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

The Package Manager of CODESYS Development System 3 before 3.5.17.0 does not check the validity of packages before installation and may be used to install CODESYS packages with malicious content.

## Which versions are affected by CVE-2021-29240?

It affects 1 product.


Products: Codesys Development System.

## How do I fix CVE-2021-29240?

No fix has been published for CVE-2021-29240 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-29240 being exploited?

There is no known exploitation of CVE-2021-29240 in the wild and no public exploit code.

## Other vulnerabilities in n/a

- [CVE-2023-3663](https://insights.sbomify.com/CVE-2023-3663/): CODESYS: Missing integrity check in CODESYS Development System (high 8.8)
- [CVE-2021-21863](https://insights.sbomify.com/CVE-2021-21863/): Deserialization in CODESYS (high 8.8)
- [CVE-2021-21865](https://insights.sbomify.com/CVE-2021-21865/): Deserialization in CODESYS (high 8.8)
- [CVE-2021-21866](https://insights.sbomify.com/CVE-2021-21866/): Deserialization in CODESYS (high 8.8)
- [CVE-2026-44468](https://insights.sbomify.com/CVE-2026-44468/): Incorrect Default Permissions in CODESYS Development System (high 8.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-29240 and fix it if it is affected.

What it is: CVE-2021-29240 is a high-severity code injection vulnerability in n/a, published on 4 May 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-2021-29240 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-2021-29240/ (Markdown: https://insights.sbomify.com/CVE-2021-29240/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-29240
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-29240
- OSV: https://osv.dev/vulnerability/CVE-2021-29240

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-29240/
Summaries are generated and may contain mistakes; the official description above is the record.