# CVE-2023-22921: Cross-site scripting in NBG-418N v2 firmware

> An authenticated administrator can inject malicious scripts via the web interface, causing denial-of-service conditions on the Zyxel router.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 1 May 2023
- **Updated:** 30 Jan 2025
- **Also known as:** GHSA-8rhh-pq82-8f6m

## What is CVE-2023-22921?

CVE-2023-22921 is a high-severity cross-site scripting vulnerability in Zyxel NBG-418N v2 firmware, published on 1 May 2023. An attacker needs administrator access to exploit it, and only if a user opens a file or follows a link.

### Official description

A cross-site scripting (XSS) vulnerability in the Zyxel NBG-418N v2 firmware versions prior to V1.00(AARP.14)C0 could allow a remote authenticated attacker with administrator privileges to store malicious scripts using a web management interface parameter, resulting in denial-of-service (DoS) conditions on an affected device.

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

## Which versions are affected by CVE-2023-22921?

It affects 1 product.


Products: Zyxel Nbg-418n Firmware.

## How do I fix CVE-2023-22921?

No fix has been published for CVE-2023-22921 yet. Limit exposure of the affected software until one is available.

## Is CVE-2023-22921 being exploited?

There is no known exploitation of CVE-2023-22921 in the wild and no public exploit code.

## Other vulnerabilities in Zyxel NBG-418N v2 firmware

- [CVE-2019-6710](https://insights.sbomify.com/CVE-2019-6710/): Cross-site request forgery in n/a (high 8.8)
- [CVE-2015-7283](https://insights.sbomify.com/CVE-2015-7283/): Hardcoded credentials in n/a (high 8.1)
- [CVE-2023-22922](https://insights.sbomify.com/CVE-2023-22922/): Memory corruption in NBG-418N v2 firmware (high 7.5)
- [CVE-2023-22923](https://insights.sbomify.com/CVE-2023-22923/): Other in NBG-418N v2 firmware (medium 6.5)
- [CVE-2022-45441](https://insights.sbomify.com/CVE-2022-45441/): Cross-site scripting in NBG-418N v2 firmware (medium 6.1)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-22921 and fix it if it is affected.

What it is: CVE-2023-22921 is a high-severity cross-site scripting vulnerability in Zyxel NBG-418N v2 firmware, published on 1 May 2023. An attacker needs administrator access to exploit it, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2023-22921 in the wild and no public exploit code.

Affected product: Zyxel NBG-418N v2 firmware. 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-2023-22921/ (Markdown: https://insights.sbomify.com/CVE-2023-22921/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-22921
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-22921
- OSV: https://osv.dev/vulnerability/CVE-2023-22921

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-22921/
Summaries are generated and may contain mistakes; the official description above is the record.