# CVE-2019-10977: Denial of service in MELSEC-Q series Ethernet module

> An attacker can cause a denial-of-service condition on Mitsubishi MELSEC-Q Ethernet modules by sending crafted TCP packets to the FTP service.

- **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:** 23 May 2019
- **Updated:** 4 Aug 2024
- **Also known as:** GHSA-3fgw-638m-mm8f

## What is CVE-2019-10977?

CVE-2019-10977 is a high-severity denial of service vulnerability in Mitsubishi Electric MELSEC-Q series Ethernet module, published on 23 May 2019. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

In Mitsubishi Electric MELSEC-Q series Ethernet module QJ71E71-100 serial number 20121 and prior, an attacker could send crafted TCP packets against the FTP service, forcing the target devices to enter an error mode and cause a denial-of-service condition.

Weakness: CWE-755 (Improper Handling of Exceptional Conditions), CWE-400 (Uncontrolled Resource Consumption)

## Which versions are affected by CVE-2019-10977?

It affects 1 product.


Products: Mitsubishielectric Qj71e71-100 Firmware.

## How do I fix CVE-2019-10977?

No fix has been published for CVE-2019-10977 yet. Limit exposure of the affected software until one is available.

## Is CVE-2019-10977 being exploited?

There is no known exploitation of CVE-2019-10977 in the wild and no public exploit code.

## Other vulnerabilities in Mitsubishi Electric MELSEC-Q series Ethernet module

- [CVE-2016-8368](https://insights.sbomify.com/CVE-2016-8368/): Denial of service in Mitsubishi Electric MELSEC-Q Series Ethernet Interface Module (high 8.6)
- [CVE-2016-8370](https://insights.sbomify.com/CVE-2016-8370/): Weak cryptography in Mitsubishi Electric MELSEC-Q Series Ethernet Interface Module (high 7.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2019-10977 and fix it if it is affected.

What it is: CVE-2019-10977 is a high-severity denial of service vulnerability in Mitsubishi Electric MELSEC-Q series Ethernet module, published on 23 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-2019-10977 in the wild and no public exploit code.

Affected product: Mitsubishi Electric MELSEC-Q series Ethernet module. 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-2019-10977/ (Markdown: https://insights.sbomify.com/CVE-2019-10977/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2019-10977
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2019-10977
- OSV: https://osv.dev/vulnerability/CVE-2019-10977

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From sbomify Insights: https://insights.sbomify.com/CVE-2019-10977/
Summaries are generated and may contain mistakes; the official description above is the record.