# CVE-2023-4699: Missing authorization in MELSEC L Series LD77MS16

> Remote unauthenticated attackers can execute arbitrary commands on Mitsubishi PLCs and CNCs, leading to data theft, modification, or denial of service.

- **Severity:** Critical 10.0 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/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:** 6 Nov 2023
- **Updated:** 16 Dec 2025
- **Also known as:** GHSA-q8jx-8wr3-gv52

## What is CVE-2023-4699?

CVE-2023-4699 is a critical missing authorization vulnerability in Mitsubishi Electric Corporation MELSEC L Series LD77MS16, published on 6 Nov 2023. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Missing Authentication for Critical Function vulnerability in Mitsubishi Electric Corporation MELSEC-F Series CPU modules, MELSEC iQ-F Series, MELSEC iQ-R series CPU modules, MELSEC iQ-R series, MELSEC iQ-L series, MELSEC Q series, MELSEC-L series, Mitsubishi Electric CNC M800V/M80V series, Mitsubishi Electric CNC M800/M80/E80 series and Mitsubishi Electric CNC M700V/M70V/E70 series allows a remote unauthenticated attacker to execute arbitrary commands by sending specific packets to the affected products. This could lead to disclose or tamper with information by reading or writing control programs, or cause a denial-of-service (DoS) condition on the products by resetting the memory contents of the products to factory settings or resetting the products remotely.

Weakness: CWE-345 (Insufficient Verification of Data Authenticity), CWE-306 (Missing Authentication for Critical Functionality)

## Which versions are affected by CVE-2023-4699?

It affects 216 products.


Products: Mitsubishielectric Fx3g-14mr\/Ds Firmware, Mitsubishielectric Fx3g-14mr\/Es-a Firmware, Mitsubishielectric Fx3g-14mr\/Es Firmware, Mitsubishielectric Fx3g-14mt\/Ds Firmware, Mitsubishielectric Fx3g-14mt\/Dss Firmware, Mitsubishielectric Fx3g-14mt\/Es-a Firmware, Mitsubishielectric Fx3g-14mt\/Es Firmware, Mitsubishielectric Fx3g-14mt\/Ess Firmware, Mitsubishielectric Fx3g-24mr\/Ds Firmware, Mitsubishielectric Fx3g-24mr\/Es-a Firmware, Mitsubishielectric Fx3g-24mr\/Es Firmware, Mitsubishielectric Fx3g-24mt\/Ds Firmware, Mitsubishielectric Fx3g-24mt\/Dss Firmware, Mitsubishielectric Fx3g-24mt\/Es-a Firmware, Mitsubishielectric Fx3g-24mt\/Es Firmware, Mitsubishielectric Fx3g-24mt\/Ess Firmware, Mitsubishielectric Fx3g-40mr\/Ds Firmware, Mitsubishielectric Fx3g-40mr\/Es-a Firmware, Mitsubishielectric Fx3g-40mr\/Es Firmware, Mitsubishielectric Fx3g-40mt\/Ds Firmware and 196 more.

## How do I fix CVE-2023-4699?

No fix has been published for CVE-2023-4699 yet. Limit exposure of the affected software until one is available.

## Is CVE-2023-4699 being exploited?

There is no known exploitation of CVE-2023-4699 in the wild and no public exploit code.

Public exploit code:

- This code functionally approximates the Citrix Bleed vulnerability (CVE-2023-4699). (github_poc): https://github.com/Scottzxor/Citrix-Bleed-Buffer-Overread-Demo

## Other vulnerabilities in Mitsubishi Electric Corporation MELSEC L Series LD77MS16

- [CVE-2023-2846](https://insights.sbomify.com/CVE-2023-2846/): Authentication Bypass Vulnerability in MELSEC-F Series main module (high 7.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-4699 and fix it if it is affected.

What it is: CVE-2023-4699 is a critical missing authorization vulnerability in Mitsubishi Electric Corporation MELSEC L Series LD77MS16, published on 6 Nov 2023. 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-2023-4699 in the wild and no public exploit code.

Affected product: Mitsubishi Electric Corporation MELSEC L Series LD77MS16. 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-2023-4699/ (Markdown: https://insights.sbomify.com/CVE-2023-4699/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-4699
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-4699
- OSV: https://osv.dev/vulnerability/CVE-2023-4699

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From sbomify Insights: https://insights.sbomify.com/CVE-2023-4699/
Summaries are generated and may contain mistakes; the official description above is the record.