# CVE-2018-19943: QNAP NAS File Station Cross-Site Scripting

> Remote attackers can inject malicious scripts into QNAP NAS web interfaces, potentially leading to code execution or account takeover.

- **Severity:** High 8.0 (`CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:H/I:H/A:H`)
- **Exploited in the wild:** Yes, since 24 May 2022 (CISA KEV), used in ransomware
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 28 Oct 2020
- **Updated:** 13 Aug 2026
- **Also known as:** GHSA-wh89-fj9h-4gr8

## What is CVE-2018-19943?

CVE-2018-19943 is a high-severity cross-site scripting vulnerability in Qnap Qts, published on 28 Oct 2020. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.

### Official description

If exploited, this cross-site scripting vulnerability could allow remote attackers to inject malicious code. QNAP has already fixed these issues in the following QTS versions. QTS 4.4.2.1270 build 20200410 and later QTS 4.4.1.1261 build 20200330 and later QTS 4.3.6.1263 build 20200330 and later QTS 4.3.4.1282 build 20200408 and later QTS 4.3.3.1252 build 20200409 and later QTS 4.2.6 build 20200421 and later

Weakness: CWE-80 (Improper Neutralization of Script-Related HTML Tags in a Web Page), CWE-79 (Improper Neutralization of Input During Web Page Generation)

## Which versions are affected by CVE-2018-19943?

It affects 1 product.


Products: Qnap Qts.

## How do I fix CVE-2018-19943?

No fix has been published for CVE-2018-19943 yet. Limit exposure of the affected software until one is available. US federal agencies must fix it by 14 Jun 2022.

## Is CVE-2018-19943 being exploited?

Yes. Attackers have exploited CVE-2018-19943 in the wild since at least 24 May 2022, including in ransomware campaigns.

## Other vulnerabilities in Qnap Qts

- [CVE-2020-2509](https://insights.sbomify.com/CVE-2020-2509/): QNAP Network-Attached Storage (NAS) Command Injection (critical 9.8, exploited in the wild)
- [CVE-2018-19949](https://insights.sbomify.com/CVE-2018-19949/): QNAP NAS File Station Command Injection (critical 9.8, exploited in the wild)
- [CVE-2019-7193](https://insights.sbomify.com/CVE-2019-7193/): QNAP QTS Improper Input Validation (critical 9.8, exploited in the wild)
- [CVE-2018-19953](https://insights.sbomify.com/CVE-2018-19953/): QNAP NAS File Station Cross-Site Scripting (medium 6.1, exploited in the wild)
- [CVE-2024-32766](https://insights.sbomify.com/CVE-2024-32766/): QTS, QuTS hero, QuTScloud (critical 10.0)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2018-19943 and fix it if it is affected.

What it is: CVE-2018-19943 is a high-severity cross-site scripting vulnerability in Qnap Qts, published on 28 Oct 2020. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Exploitation: Yes. Attackers have exploited CVE-2018-19943 in the wild since at least 24 May 2022, including in ransomware campaigns.

Affected product: Qnap Qts. 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-2018-19943/ (Markdown: https://insights.sbomify.com/CVE-2018-19943/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2018-19943
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2018-19943
- OSV: https://osv.dev/vulnerability/CVE-2018-19943

---
From sbomify Insights: https://insights.sbomify.com/CVE-2018-19943/
Summaries are generated and may contain mistakes; the official description above is the record.