# CVE-2025-34117: Netcore / Netis Routers RCE via UDP Port 53413 Backdoor

> Unauthenticated attackers can execute arbitrary commands on Netcore and Netis routers via a backdoor UDP listener, requiring firmware updates to mitigate.

- **Severity:** Critical 9.3 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 16 Jul 2025
- **Updated:** 7 Apr 2026
- **Also known as:** GHSA-86xp-hg9p-72mv

## What is CVE-2025-34117?

CVE-2025-34117 is a critical command injection vulnerability in Netcore Technology Router firmware, published on 16 Jul 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A remote code execution vulnerability exists in multiple Netcore and Netis routers models with firmware released prior to August 2014 due to the presence of an undocumented backdoor listener on UDP port 53413. Exact version boundaries remain undocumented. An unauthenticated remote attacker can send specially crafted UDP packets to execute arbitrary commands on the affected device. This backdoor uses a hardcoded authentication mechanism and accepts shell commands post-authentication. Some device models include a non-standard implementation of the `echo` command, which may affect exploitability.

Weakness: CWE-912 (Hidden Functionality), CWE-78 (Improper Neutralization of Special Elements used in an OS Command), CWE-306 (Missing Authentication for Critical Functionality)

## Which versions are affected by CVE-2025-34117?


## How do I fix CVE-2025-34117?

No fix has been published for CVE-2025-34117 yet. Limit exposure of the affected software until one is available.

## Is CVE-2025-34117 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2025-34117 exists.

Public exploit code:

- Netcore Router Udp 53413 Backdoor (metasploit)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-34117 and fix it if it is affected.

What it is: CVE-2025-34117 is a critical command injection vulnerability in Netcore Technology Router firmware, published on 16 Jul 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2025-34117 exists.

Affected product: Netcore Technology Router firmware. 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-2025-34117/ (Markdown: https://insights.sbomify.com/CVE-2025-34117/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-34117
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-34117
- OSV: https://osv.dev/vulnerability/CVE-2025-34117

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-34117/
Summaries are generated and may contain mistakes; the official description above is the record.