# CVE-2019-6811: Denial of service in Modicon Quantum 140 NOE771x1

> A remote attacker can cause a denial of service on Schneider Modicon Quantum modules by sending oversized fragmented IP packets, requiring a power cycle to recover.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/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:** 17 Sep 2019
- **Updated:** 4 Aug 2024
- **Also known as:** GHSA-3xxj-wpwj-gxhm

## What is CVE-2019-6811?

CVE-2019-6811 is a high-severity denial of service vulnerability in Schneider Electric SE Modicon Quantum 140 NOE771x1, published on 17 Sep 2019. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

An Improper Check for Unusual or Exceptional Conditions (CWE-754) vulnerability exists in Modicon Quantum 140 NOE771x1 version 6.9 and earlier, which could cause denial of service when the module receives an IP fragmented packet with a length greater than 65535 bytes. The module then requires a power cycle to recover.

Weakness: CWE-754 (Improper Check for Unusual or Exceptional Conditions)

## Which versions are affected by CVE-2019-6811?

It affects 2 products.


Products: Schneider-Electric Modicon Quantum 140noe77101 Firmware, Schneider-Electric Modicon Quantum 140noe77111 Firmware.

## How do I fix CVE-2019-6811?

No fix has been published for CVE-2019-6811 yet. Limit exposure of the affected software until one is available.

## Is CVE-2019-6811 being exploited?

There is no known exploitation of CVE-2019-6811 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2019-6811 and fix it if it is affected.

What it is: CVE-2019-6811 is a high-severity denial of service vulnerability in Schneider Electric SE Modicon Quantum 140 NOE771x1, published on 17 Sep 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-2019-6811 in the wild and no public exploit code.

Affected product: Schneider Electric SE Modicon Quantum 140 NOE771x1. 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-2019-6811/ (Markdown: https://insights.sbomify.com/CVE-2019-6811/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2019-6811
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2019-6811
- OSV: https://osv.dev/vulnerability/CVE-2019-6811

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From sbomify Insights: https://insights.sbomify.com/CVE-2019-6811/
Summaries are generated and may contain mistakes; the official description above is the record.