# CVE-2019-25378: Smoothwall Express 3.1 'proxy.cgi' Cross-Site Scripting

> Attackers can inject malicious scripts into the proxy configuration page, allowing arbitrary JavaScript execution in users' browsers.

- **Severity:** Medium 5.1 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/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-hcvh-8pvq-9ppx

## What is CVE-2019-25378?

CVE-2019-25378 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 cross-site scripting vulnerabilities in the proxy.cgi endpoint that allow attackers to inject malicious scripts through parameters including CACHE_SIZE, MAX_SIZE, MIN_SIZE, MAX_OUTGOING_SIZE, and MAX_INCOMING_SIZE. Attackers can submit POST requests with script payloads to store or reflect arbitrary JavaScript code that executes in users' browsers when the proxy configuration page is accessed.

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

## Which versions are affected by CVE-2019-25378?

It affects 1 product.


Products: Smoothwall Smoothwall Express.

## How do I fix CVE-2019-25378?

No fix has been published for CVE-2019-25378 yet. Limit exposure of the affected software until one is available.

## Is CVE-2019-25378 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2019-25378 exists.

## 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-2019-25394](https://insights.sbomify.com/CVE-2019-25394/): Smoothwall Express 3.1 'modem.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)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2019-25378 and fix it if it is affected.

What it is: CVE-2019-25378 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: It is not confirmed as exploited in the wild, but public exploit code for CVE-2019-25378 exists.

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-2019-25378/ (Markdown: https://insights.sbomify.com/CVE-2019-25378/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2019-25378
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2019-25378
- OSV: https://osv.dev/vulnerability/CVE-2019-25378

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From sbomify Insights: https://insights.sbomify.com/CVE-2019-25378/
Summaries are generated and may contain mistakes; the official description above is the record.