# CVE-2024-4020: Tenda FH1206 addressNat fromAddressNat buffer overflow

> Remote attackers can trigger a buffer overflow in the Tenda FH1206 router's addressNat function, potentially leading to code execution or service disruption.

- **Severity:** High 8.8 (`CVSS:3.1/AV:N/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:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 20 Apr 2024
- **Updated:** 1 Aug 2024
- **Also known as:** GHSA-rw9j-38rq-r4wq

## What is CVE-2024-4020?

CVE-2024-4020 is a high-severity memory corruption vulnerability in Tenda FH1206, published on 20 Apr 2024. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

A vulnerability was found in Tenda FH1206 1.2.0.8(8155) and classified as critical. This issue affects the function fromAddressNat of the file /goform/addressNat. The manipulation of the argument entrys leads to buffer overflow. The attack may be initiated remotely. The exploit has been disclosed to the public and may be used. The associated identifier of this vulnerability is VDB-261671. NOTE: The vendor was contacted early about this disclosure but did not respond in any way.

Weakness: CWE-787 (Out-of-bounds Write), CWE-120 (Buffer Copy without Checking Size of Input)

## Which versions are affected by CVE-2024-4020?

It affects 1 product.


Products: Tenda Fh1206 Firmware.

## How do I fix CVE-2024-4020?

No fix has been published for CVE-2024-4020 yet. Limit exposure of the affected software until one is available.

## Is CVE-2024-4020 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2024-4020 exists.

## Other vulnerabilities in Tenda FH1206

- [CVE-2024-42978](https://insights.sbomify.com/CVE-2024-42978/): Command injection in n/a (critical 9.8)
- [CVE-2024-35339](https://insights.sbomify.com/CVE-2024-35339/): Command injection in n/a (critical 9.8)
- [CVE-2024-34943](https://insights.sbomify.com/CVE-2024-34943/): Memory corruption in n/a (critical 9.8)
- [CVE-2024-34945](https://insights.sbomify.com/CVE-2024-34945/): Memory corruption in n/a (critical 9.8)
- [CVE-2024-33215](https://insights.sbomify.com/CVE-2024-33215/): Memory corruption in n/a (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2024-4020 and fix it if it is affected.

What it is: CVE-2024-4020 is a high-severity memory corruption vulnerability in Tenda FH1206, published on 20 Apr 2024. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2024-4020 exists.

Affected product: Tenda FH1206. 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-2024-4020/ (Markdown: https://insights.sbomify.com/CVE-2024-4020/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2024-4020
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-4020
- OSV: https://osv.dev/vulnerability/CVE-2024-4020

---
From sbomify Insights: https://insights.sbomify.com/CVE-2024-4020/
Summaries are generated and may contain mistakes; the official description above is the record.