# CVE-2025-4120: Netgear JWNR2000v2 sub_4238E8 buffer overflow

> Remote attackers can trigger a buffer overflow in the Netgear JWNR2000v2 router via the host argument, potentially leading to code execution.

- **Severity:** High 8.7 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 30 Apr 2025
- **Updated:** 30 Apr 2025
- **Also known as:** GHSA-q66q-qwxm-vgrg

## What is CVE-2025-4120?

CVE-2025-4120 is a high-severity memory corruption vulnerability in Netgear JWNR2000v2, published on 30 Apr 2025. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

A vulnerability was found in Netgear JWNR2000v2 1.0.0.11. It has been classified as critical. Affected is the function sub_4238E8. The manipulation of the argument host leads to buffer overflow. It is possible to launch the attack remotely. The vendor was contacted early about this disclosure but did not respond in any way.

Weakness: CWE-120 (Buffer Copy without Checking Size of Input), CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer)

## Which versions are affected by CVE-2025-4120?

It affects 1 product.


Products: Netgear Jwnr2000v2 Firmware.

## How do I fix CVE-2025-4120?

No fix has been published for CVE-2025-4120 yet. Limit exposure of the affected software until one is available.

## Is CVE-2025-4120 being exploited?

There is no known exploitation of CVE-2025-4120 in the wild and no public exploit code.

## Other vulnerabilities in Netgear JWNR2000v2

- [CVE-2023-38922](https://insights.sbomify.com/CVE-2023-38922/): Memory corruption in n/a (high 8.8)
- [CVE-2023-39550](https://insights.sbomify.com/CVE-2023-39550/): Memory corruption in n/a (high 8.8)
- [CVE-2025-4121](https://insights.sbomify.com/CVE-2025-4121/): Netgear JWNR2000v2 cmd_wireless command injection (medium 5.3)
- [CVE-2025-4122](https://insights.sbomify.com/CVE-2025-4122/): Netgear JWNR2000v2 sub_435E04 command injection (medium 5.3)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-4120 and fix it if it is affected.

What it is: CVE-2025-4120 is a high-severity memory corruption vulnerability in Netgear JWNR2000v2, published on 30 Apr 2025. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2025-4120 in the wild and no public exploit code.

Affected product: Netgear JWNR2000v2. 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-2025-4120/ (Markdown: https://insights.sbomify.com/CVE-2025-4120/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-4120
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-4120
- OSV: https://osv.dev/vulnerability/CVE-2025-4120

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-4120/
Summaries are generated and may contain mistakes; the official description above is the record.