# CVE-2019-25394: Smoothwall Express 3.1 'modem.cgi' Cross-Site Scripting

> Attackers can inject malicious scripts via POST parameters in modem.cgi, leading to arbitrary JavaScript execution in users' browsers.

- **Severity:** Medium 5.3 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 16 Feb 2026
- **Updated:** 5 Mar 2026
- **Also known as:** GHSA-qcc6-w9r3-h3c3

## What is CVE-2019-25394?

CVE-2019-25394 is a medium-severity cross-site scripting vulnerability in Smoothwall Express, published on 16 Feb 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

Smoothwall Express 3.1-SP4-polar-x86_64-update9 contains multiple stored cross-site scripting vulnerabilities in the modem.cgi script that allow attackers to inject malicious scripts through POST parameters. Attackers can submit crafted payloads in parameters like INIT, HANGUP, SPEAKER_ON, SPEAKER_OFF, TONE_DIAL, and PULSE_DIAL to execute arbitrary JavaScript in users' browsers when the stored data is retrieved.

Weakness: CWE-79 (Improper Neutralization of Input During Web Page Generation)

## Which versions are affected by CVE-2019-25394?

It affects 1 product.


Products: Smoothwall Smoothwall Express.

## How do I fix CVE-2019-25394?

No fix has been published for CVE-2019-25394 yet. Limit exposure of the affected software until one is available.

## Is CVE-2019-25394 being exploited?

There is no known exploitation of CVE-2019-25394 in the wild and no public exploit code.

## Other vulnerabilities in Smoothwall Express

- [CVE-2011-1085](https://insights.sbomify.com/CVE-2011-1085/): Cross-site request forgery in Smoothwall Express (high 8.8)
- [CVE-2011-1084](https://insights.sbomify.com/CVE-2011-1084/): Cross-site scripting in Smoothwall Express (medium 6.1)
- [CVE-2019-25379](https://insights.sbomify.com/CVE-2019-25379/): Smoothwall Express 3.1 'urlfilter.cgi' Cross-Site Scripting (medium 5.3)
- [CVE-2019-25395](https://insights.sbomify.com/CVE-2019-25395/): Smoothwall Express 3.1 'preferences.cgi' Cross-Site Scripting (medium 5.3)
- [CVE-2026-26352](https://insights.sbomify.com/CVE-2026-26352/): Smoothwall Express < 3.1 Update 13 Stored XSS in vpnmain.cgi via VPN_IP Parameter (medium 5.1)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2019-25394 and fix it if it is affected.

What it is: CVE-2019-25394 is a medium-severity cross-site scripting vulnerability in Smoothwall Express, published on 16 Feb 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2019-25394 in the wild and no public exploit code.

Affected product: Smoothwall Express. 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-2019-25394/ (Markdown: https://insights.sbomify.com/CVE-2019-25394/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2019-25394
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2019-25394
- OSV: https://osv.dev/vulnerability/CVE-2019-25394

---
From sbomify Insights: https://insights.sbomify.com/CVE-2019-25394/
Summaries are generated and may contain mistakes; the official description above is the record.