# CVE-2023-4625: Denial-of-Service（DoS） Vulnerability in Web server function on MELSEC Series CPU module

> Remote attackers can lock out legitimate users from the Web server interface by triggering excessive authentication attempt restrictions.

- **Severity:** Medium 5.3 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L`)
- **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:** 27 Feb 2025
- **Also known as:** GHSA-23wc-j7fg-6xp5

## What is CVE-2023-4625?

CVE-2023-4625 is a medium-severity denial of service vulnerability in Mitsubishi Electric Corporation MELSEC iQ-F Series FX5S-30MR/ES, published on 6 Nov 2023. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Improper Restriction of Excessive Authentication Attempts vulnerability in Mitsubishi Electric Corporation MELSEC iQ-F/iQ-R Series CPU modules Web server function allows a remote unauthenticated attacker to prevent legitimate users from logging into the Web server function for a certain period after the attacker has attempted to log in illegally by continuously attempting unauthorized login to the Web server function. The impact of this vulnerability will persist while the attacker continues to attempt unauthorized login.

Weakness: CWE-307 (Improper Restriction of Excessive Authentication Attempts)

## Which versions are affected by CVE-2023-4625?

It affects 63 products.


Products: Mitsubishielectric Fx5s-30mr\/Es Firmware, Mitsubishielectric Fx5s-30mt\/Es Firmware, Mitsubishielectric Fx5s-30mt\/Ess Firmware, Mitsubishielectric Fx5s-40mr\/Es Firmware, Mitsubishielectric Fx5s-40mt\/Es Firmware, Mitsubishielectric Fx5s-40mt\/Ess Firmware, Mitsubishielectric Fx5s-60mr\/Es Firmware, Mitsubishielectric Fx5s-60mt\/Es Firmware, Mitsubishielectric Fx5s-60mt\/Ess Firmware, Mitsubishielectric Fx5s-80mr\/Es Firmware, Mitsubishielectric Fx5s-80mt\/Es Firmware, Mitsubishielectric Fx5s-80mt\/Ess Firmware, Mitsubishielectric Fx5u-32mr\/Ds Firmware, Mitsubishielectric Fx5u-32mr\/Es Firmware, Mitsubishielectric Fx5u-32mt\/Ds Firmware, Mitsubishielectric Fx5u-32mt\/Dss Firmware, Mitsubishielectric Fx5u-32mt\/Es Firmware, Mitsubishielectric Fx5u-32mt\/Ess Firmware, Mitsubishielectric Fx5u-64mr\/Ds Firmware, Mitsubishielectric Fx5u-64mr\/Es Firmware and 43 more.

## How do I fix CVE-2023-4625?

No fix has been published for CVE-2023-4625 yet. Limit exposure of the affected software until one is available.

## Is CVE-2023-4625 being exploited?

There is no known exploitation of CVE-2023-4625 in the wild and no public exploit code.

## Other vulnerabilities in Mitsubishi Electric Corporation MELSEC iQ-F Series FX5S-30MR/ES

- [CVE-2022-40267](https://insights.sbomify.com/CVE-2022-40267/): Authentication Bypass Vulnerability in Web Server Function on MELSEC Series (medium 5.9)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-4625 and fix it if it is affected.

What it is: CVE-2023-4625 is a medium-severity denial of service vulnerability in Mitsubishi Electric Corporation MELSEC iQ-F Series FX5S-30MR/ES, 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-2023-4625 in the wild and no public exploit code.

Affected product: Mitsubishi Electric Corporation MELSEC iQ-F Series FX5S-30MR/ES. 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-2023-4625/ (Markdown: https://insights.sbomify.com/CVE-2023-4625/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-4625
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-4625
- OSV: https://osv.dev/vulnerability/CVE-2023-4625

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-4625/
Summaries are generated and may contain mistakes; the official description above is the record.