# CVE-2019-6816: Code injection in Modicon Quantum - all firmware versions

> Attackers can inject code via Modbus to modify firmware and cause denial of service on Modicon Quantum PLCs.

- **Severity:** Critical 9.1 (`CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/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:** 22 May 2019
- **Updated:** 4 Aug 2024
- **Also known as:** GHSA-cc47-9r7p-x4hv

## What is CVE-2019-6816?

CVE-2019-6816 is a critical code injection vulnerability in Modicon Quantum - all firmware versions, published on 22 May 2019. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

In Modicon Quantum all firmware versions, a CWE-94: Code Injection vulnerability could cause an unauthorized firmware modification with possible Denial of Service when using Modbus protocol.

Weakness: CWE-94 (Improper Control of Generation of Code)

## Which versions are affected by CVE-2019-6816?

It affects 1 product.


Products: Schneider-Electric Modicon Quantum Firmware.

## How do I fix CVE-2019-6816?

No fix has been published for CVE-2019-6816 yet. Limit exposure of the affected software until one is available.

## Is CVE-2019-6816 being exploited?

There is no known exploitation of CVE-2019-6816 in the wild and no public exploit code.

## Other vulnerabilities in Modicon Quantum - all firmware versions

- [CVE-2019-6815](https://insights.sbomify.com/CVE-2019-6815/): Missing authorization in Modicon Quantum - all firmware versions (critical 9.1)
- [CVE-2018-7788](https://insights.sbomify.com/CVE-2018-7788/): Denial of service in Modicon Quantum with firmware versions prior to V2.40. (medium 6.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2019-6816 and fix it if it is affected.

What it is: CVE-2019-6816 is a critical code injection vulnerability in Modicon Quantum - all firmware versions, published on 22 May 2019. 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-2019-6816 in the wild and no public exploit code.

Affected product: Modicon Quantum - all firmware versions. 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-2019-6816/ (Markdown: https://insights.sbomify.com/CVE-2019-6816/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2019-6816
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2019-6816
- OSV: https://osv.dev/vulnerability/CVE-2019-6816

---
From sbomify Insights: https://insights.sbomify.com/CVE-2019-6816/
Summaries are generated and may contain mistakes; the official description above is the record.