# CVE-2023-40478: NETGEAR RAX30 Telnet CLI passwd Stack-based Buffer Overflow Remote Code Execution Vulnerability

> Network-adjacent attackers can execute arbitrary code as root on NETGEAR RAX30 routers via a stack-based buffer overflow in the Telnet CLI.

- **Severity:** High 8.0 (`CVSS:3.0/AV:A/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 3 May 2024
- **Updated:** 2 Aug 2024
- **Also known as:** GHSA-pq3r-x8gq-g8xm

## What is CVE-2023-40478?

CVE-2023-40478 is a high-severity memory corruption vulnerability in NETGEAR RAX30, published on 3 May 2024. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

NETGEAR RAX30 Telnet CLI passwd Stack-based Buffer Overflow Remote Code Execution Vulnerability. This vulnerability allows network-adjacent attackers to execute arbitrary code on affected installations of NETGEAR RAX30 routers. Although authentication is required to exploit this vulnerability, the existing authentication mechanism can be bypassed.

The specific flaw exists within the telnet CLI service, which listens on TCP port 23. The issue results from the lack of proper validation of the length of user-supplied data prior to copying it to a fixed-length stack-based buffer. An attacker can leverage this vulnerability to execute code in the context of root. Was ZDI-CAN-20009.

Weakness: CWE-787 (Out-of-bounds Write), CWE-121 (Stack-based Buffer Overflow)

## Which versions are affected by CVE-2023-40478?

It affects 1 product.


Products: Netgear Rax30 Firmware.

## How do I fix CVE-2023-40478?

No fix has been published for CVE-2023-40478 yet. Limit exposure of the affected software until one is available.

## Is CVE-2023-40478 being exploited?

There is no known exploitation of CVE-2023-40478 in the wild and no public exploit code.

## Other vulnerabilities in NETGEAR RAX30

- [CVE-2025-44658](https://insights.sbomify.com/CVE-2025-44658/): File upload in n/a (critical 9.8)
- [CVE-2023-1327](https://insights.sbomify.com/CVE-2023-1327/): Auth bypass in Netgear RAX30 (AX2400) (critical 9.8)
- [CVE-2023-27852](https://insights.sbomify.com/CVE-2023-27852/): Memory corruption in NETGEAR Nighthawk WiFi6 Router (critical 9.8)
- [CVE-2023-27853](https://insights.sbomify.com/CVE-2023-27853/): Other in NETGEAR Nighthawk WiFi6 Router (critical 9.8)
- [CVE-2023-51635](https://insights.sbomify.com/CVE-2023-51635/): NETGEAR RAX30 fing_dil Stack-based Buffer Overflow Remote Code Execution Vulnerability (high 8.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-40478 and fix it if it is affected.

What it is: CVE-2023-40478 is a high-severity memory corruption vulnerability in NETGEAR RAX30, published on 3 May 2024. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2023-40478 in the wild and no public exploit code.

Affected product: NETGEAR RAX30. 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-2023-40478/ (Markdown: https://insights.sbomify.com/CVE-2023-40478/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-40478
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-40478
- OSV: https://osv.dev/vulnerability/CVE-2023-40478

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-40478/
Summaries are generated and may contain mistakes; the official description above is the record.