# CVE-2016-8370: Weak cryptography in Mitsubishi Electric MELSEC-Q Series Ethernet Interface Module

> Weak encryption of transmitted passwords in Mitsubishi MELSEC-Q PLC modules allows attackers to potentially intercept credentials and bypass security controls.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 13 Feb 2017
- **Updated:** 6 Aug 2024
- **Also known as:** GHSA-48g9-whq4-7wfg

## What is CVE-2016-8370?

CVE-2016-8370 is a high-severity vulnerability in Mitsubishi Electric MELSEC-Q Series Ethernet Interface Module, published on 13 Feb 2017. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

An issue was discovered in Mitsubishi Electric Automation MELSEC-Q series Ethernet interface modules QJ71E71-100, all versions, QJ71E71-B5, all versions, and QJ71E71-B2, all versions. Weakly encrypted passwords are transmitted to a MELSEC-Q PLC.

Weakness: CWE-327 (Use of a Broken or Risky Cryptographic Algorithm)

## Which versions are affected by CVE-2016-8370?

It affects 3 products.


Products: Mitsubishielectric Qj71e71-100 Firmware, Mitsubishielectric Qj71e71-B2 Firmware, Mitsubishielectric Qj71e71-B5 Firmware.

## How do I fix CVE-2016-8370?

No fix has been published for CVE-2016-8370 yet. Limit exposure of the affected software until one is available.

## Is CVE-2016-8370 being exploited?

There is no known exploitation of CVE-2016-8370 in the wild and no public exploit code.

## Other vulnerabilities in Mitsubishi Electric MELSEC-Q Series Ethernet Interface 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-2019-10977](https://insights.sbomify.com/CVE-2019-10977/): Denial of service in MELSEC-Q series Ethernet module (high 7.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2016-8370 and fix it if it is affected.

What it is: CVE-2016-8370 is a high-severity vulnerability in Mitsubishi Electric MELSEC-Q Series Ethernet Interface Module, published on 13 Feb 2017. 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-2016-8370 in the wild and no public exploit code.

Affected product: Mitsubishi Electric MELSEC-Q Series Ethernet Interface 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-2016-8370/ (Markdown: https://insights.sbomify.com/CVE-2016-8370/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2016-8370
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2016-8370
- OSV: https://osv.dev/vulnerability/CVE-2016-8370

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From sbomify Insights: https://insights.sbomify.com/CVE-2016-8370/
Summaries are generated and may contain mistakes; the official description above is the record.