# CVE-2024-3909: Tenda AC500 execCommand formexeCommand stack-based overflow

> Remote attackers can trigger a stack-based buffer overflow in the Tenda AC500 router's execCommand function to execute arbitrary code.

- **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:** 17 Apr 2024
- **Updated:** 1 Aug 2024
- **Also known as:** GHSA-8pq6-3gmg-cvrx

## What is CVE-2024-3909?

CVE-2024-3909 is a high-severity memory corruption vulnerability in Tenda AC500, published on 17 Apr 2024. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

A vulnerability classified as critical was found in Tenda AC500 2.0.1.9(1307). Affected by this vulnerability is the function formexeCommand of the file /goform/execCommand. The manipulation of the argument cmdinput leads to stack-based buffer overflow. The attack can be launched remotely. The exploit has been disclosed to the public and may be used. The identifier VDB-261145 was assigned to this vulnerability. NOTE: The vendor was contacted early about this disclosure but did not respond in any way.

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

## Which versions are affected by CVE-2024-3909?

It affects 1 product.


Products: Tenda Ac500 Firmware.

## How do I fix CVE-2024-3909?

No fix has been published for CVE-2024-3909 yet. Limit exposure of the affected software until one is available.

## Is CVE-2024-3909 being exploited?

There is no known exploitation of CVE-2024-3909 in the wild and no public exploit code.

## Other vulnerabilities in Tenda AC500

- [CVE-2024-32318](https://insights.sbomify.com/CVE-2024-32318/): Memory corruption in n/a (critical 9.8)
- [CVE-2023-25233](https://insights.sbomify.com/CVE-2023-25233/): Memory corruption in n/a (critical 9.8)
- [CVE-2023-25234](https://insights.sbomify.com/CVE-2023-25234/): Memory corruption in n/a (critical 9.8)
- [CVE-2024-3905](https://insights.sbomify.com/CVE-2024-3905/): Tenda AC500 execCommand R7WebsSecurityHandler stack-based overflow (high 8.8)
- [CVE-2024-3906](https://insights.sbomify.com/CVE-2024-3906/): Tenda AC500 QuickIndex formQuickIndex stack-based overflow (high 8.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2024-3909 and fix it if it is affected.

What it is: CVE-2024-3909 is a high-severity memory corruption vulnerability in Tenda AC500, published on 17 Apr 2024. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2024-3909 in the wild and no public exploit code.

Affected product: Tenda AC500. 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-2024-3909/ (Markdown: https://insights.sbomify.com/CVE-2024-3909/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2024-3909
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-3909
- OSV: https://osv.dev/vulnerability/CVE-2024-3909

---
From sbomify Insights: https://insights.sbomify.com/CVE-2024-3909/
Summaries are generated and may contain mistakes; the official description above is the record.