# CVE-2025-41704: Phoenix Contact: Unauthenticated Modbus Service DoS via Crafted Function Code

> Unauthenticated remote attackers can cause a denial of service on the Modbus service of Phoenix Contact UPS devices by sending crafted function codes.

- **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:** 14 Oct 2025
- **Updated:** 3 Nov 2025
- **Also known as:** GHSA-qvxv-3qg9-53cr

## What is CVE-2025-41704?

CVE-2025-41704 is a medium-severity denial of service vulnerability in Phoenix Contact QUINT4-UPS/24DC/24DC/10/EIP, published on 14 Oct 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

An unauthanticated remote attacker can perform a DoS of the Modbus service by sending a specific function and sub-function code without affecting the core functionality.

Weakness: CWE-770 (Allocation of Resources Without Limits or Throttling)

## Which versions are affected by CVE-2025-41704?


## How do I fix CVE-2025-41704?

No fix has been published for CVE-2025-41704 yet. Limit exposure of the affected software until one is available.

## Is CVE-2025-41704 being exploited?

There is no known exploitation of CVE-2025-41704 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-41704 and fix it if it is affected.

What it is: CVE-2025-41704 is a medium-severity denial of service vulnerability in Phoenix Contact QUINT4-UPS/24DC/24DC/10/EIP, published on 14 Oct 2025. 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-2025-41704 in the wild and no public exploit code.

Affected product: Phoenix Contact QUINT4-UPS/24DC/24DC/10/EIP. 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-2025-41704/ (Markdown: https://insights.sbomify.com/CVE-2025-41704/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-41704
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-41704
- OSV: https://osv.dev/vulnerability/CVE-2025-41704

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From sbomify Insights: https://insights.sbomify.com/CVE-2025-41704/
Summaries are generated and may contain mistakes; the official description above is the record.