# CVE-2019-6847: Denial of service in Modicon M580, Modicon M340, and Modicon BMxCRA / 140CRA modules (see notification for version info)

> An attacker can cause a Denial of Service on the FTP service of Modicon PLCs by uploading incompatible firmware via FTP.

- **Severity:** Medium 4.9 (`CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/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:** 29 Oct 2019
- **Updated:** 4 Aug 2024
- **Also known as:** GHSA-q2g9-886v-2wv3

## What is CVE-2019-6847?

CVE-2019-6847 is a medium-severity denial of service vulnerability in Modicon M580, Modicon M340, and Modicon BMxCRA / 140CRA modules (see notification for version info), published on 29 Oct 2019. An attacker needs administrator access to exploit it, with no action from the victim.

### Official description

A CWE-755: Improper Handling of Exceptional Conditions vulnerability exists in Modicon M580, Modicon M340, Modicon BMxCRA and 140CRA modules (all firmware versions), which could cause a Denial of Service attack on the FTP service when upgrading the firmware with a version incompatible with the application in the controller using FTP protocol.

Weakness: CWE-755 (Improper Handling of Exceptional Conditions)

## Which versions are affected by CVE-2019-6847?

It affects 4 products.


Products: Schneider-Electric Modicon 140cra Firmware, Schneider-Electric Modicon Bmxcra Firmware, Schneider-Electric Modicon M340 Firmware, Schneider-Electric Modicon M580 Firmware.

## How do I fix CVE-2019-6847?

No fix has been published for CVE-2019-6847 yet. Limit exposure of the affected software until one is available.

## Is CVE-2019-6847 being exploited?

There is no known exploitation of CVE-2019-6847 in the wild and no public exploit code.

## Other vulnerabilities in Modicon M580, Modicon M340, and Modicon BMxCRA / 140CRA modules (see notification for version info)

- [CVE-2019-6846](https://insights.sbomify.com/CVE-2019-6846/): Information disclosure in Modicon M580, Modicon M340, Modicon BMxCRA and 140CRA modules (all firmware versions) (medium 6.5)
- [CVE-2019-6841](https://insights.sbomify.com/CVE-2019-6841/): Denial of service in Modicon M580, Modicon M340, and Modicon BMxCRA / 140CRA modules (see notification for version info) (medium 4.9)
- [CVE-2019-6842](https://insights.sbomify.com/CVE-2019-6842/): Denial of service in Modicon M580, Modicon M340, and Modicon BMxCRA / 140CRA modules (see notification for version info) (medium 4.9)
- [CVE-2019-6843](https://insights.sbomify.com/CVE-2019-6843/): Denial of service in Modicon M580, Modicon M340, and Modicon BMxCRA / 140CRA modules (see notification for version info) (medium 4.9)
- [CVE-2019-6844](https://insights.sbomify.com/CVE-2019-6844/): Denial of service in Modicon M580, Modicon M340, and Modicon BMxCRA / 140CRA modules (see notification for version info) (medium 4.9)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2019-6847 and fix it if it is affected.

What it is: CVE-2019-6847 is a medium-severity denial of service vulnerability in Modicon M580, Modicon M340, and Modicon BMxCRA / 140CRA modules (see notification for version info), published on 29 Oct 2019. An attacker needs administrator access to exploit it, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2019-6847 in the wild and no public exploit code.

Affected product: Modicon M580, Modicon M340, and Modicon BMxCRA / 140CRA modules (see notification for version info). 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-2019-6847/ (Markdown: https://insights.sbomify.com/CVE-2019-6847/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2019-6847
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2019-6847
- OSV: https://osv.dev/vulnerability/CVE-2019-6847

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From sbomify Insights: https://insights.sbomify.com/CVE-2019-6847/
Summaries are generated and may contain mistakes; the official description above is the record.