# CVE-2025-4999: Linksys FGW3000-AH/FGW3000-HK HTTP POST Request sysconf.cgi sub_4153FC command injection

> Remote attackers can execute arbitrary commands on Linksys FGW3000 routers via a command injection flaw in the sysconf.cgi handler.

- **Severity:** Medium 5.3 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:L/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:** 20 May 2025
- **Updated:** 21 May 2025
- **Also known as:** GHSA-m252-h4rm-hqfr

## What is CVE-2025-4999?

CVE-2025-4999 is a medium-severity command injection vulnerability in Linksys FGW3000-AH, published on 20 May 2025. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

A vulnerability was found in Linksys FGW3000-AH and FGW3000-HK up to 1.0.17.000000 and classified as critical. Affected by this issue is the function sub_4153FC of the file /cgi-bin/sysconf.cgi of the component HTTP POST Request Handler. The manipulation of the argument supplicant_rnd_id_en leads to command injection. The attack may be launched remotely. The exploit has been disclosed to the public and may be used. The vendor was contacted early about this disclosure but did not respond in any way.

Weakness: CWE-77 (Improper Neutralization of Special Elements used in a Command), CWE-74 (Improper Neutralization of Special Elements in Output Used by a Downstream Component)

## Which versions are affected by CVE-2025-4999?

It affects 2 products.


Products: Linksys Fgw3000-Ah Firmware, Linksys Fgw3000-Hk Firmware.

## How do I fix CVE-2025-4999?

No fix has been published for CVE-2025-4999 yet. Limit exposure of the affected software until one is available.

## Is CVE-2025-4999 being exploited?

There is no known exploitation of CVE-2025-4999 in the wild and no public exploit code.

## Other vulnerabilities in Linksys FGW3000-AH

- [CVE-2025-5000](https://insights.sbomify.com/CVE-2025-5000/): Linksys FGW3000-AH/FGW3000-HK HTTP POST Request sysconf.cgi control_panel_sw command injection (medium 5.3)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-4999 and fix it if it is affected.

What it is: CVE-2025-4999 is a medium-severity command injection vulnerability in Linksys FGW3000-AH, published on 20 May 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-2025-4999 in the wild and no public exploit code.

Affected product: Linksys FGW3000-AH. 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-2025-4999/ (Markdown: https://insights.sbomify.com/CVE-2025-4999/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-4999
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-4999
- OSV: https://osv.dev/vulnerability/CVE-2025-4999

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-4999/
Summaries are generated and may contain mistakes; the official description above is the record.