# CVE-2023-27992: Zyxel Multiple NAS Devices Command Injection

> Unauthenticated attackers can execute arbitrary OS commands on Zyxel NAS devices via crafted HTTP requests, requiring firmware upgrades.

- **Severity:** Critical 9.8 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Yes, since 23 Jun 2023 (CISA KEV)
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 19 Jun 2023
- **Updated:** 21 Oct 2025
- **Also known as:** GHSA-5wv9-h9hr-4p52

## What is CVE-2023-27992?

CVE-2023-27992 is a critical command injection vulnerability in Zyxel NAS326 firmware, published on 19 Jun 2023. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

The pre-authentication command injection vulnerability in the Zyxel NAS326 firmware versions prior to V5.21(AAZF.14)C0, NAS540 firmware versions prior to V5.21(AATB.11)C0, and NAS542 firmware versions prior to V5.21(ABAG.11)C0 could allow an unauthenticated attacker to execute some operating system (OS) commands remotely by sending a crafted HTTP request.

Weakness: CWE-78 (Improper Neutralization of Special Elements used in an OS Command)

## Which versions are affected by CVE-2023-27992?

It affects 3 products.


Products: Zyxel Nas326 Firmware, Zyxel Nas540 Firmware, Zyxel Nas542 Firmware.

## How do I fix CVE-2023-27992?

No fix has been published for CVE-2023-27992 yet. Limit exposure of the affected software until one is available. US federal agencies must fix it by 14 Jul 2023.

## Is CVE-2023-27992 being exploited?

Yes. Attackers have exploited CVE-2023-27992 in the wild since at least 23 Jun 2023.

## Other vulnerabilities in Zyxel NAS326 firmware

- [CVE-2024-6342](https://insights.sbomify.com/CVE-2024-6342/): Command injection in NAS326 firmware (critical 9.8)
- [CVE-2024-29972](https://insights.sbomify.com/CVE-2024-29972/): Command injection in NAS326 firmware (critical 9.8)
- [CVE-2024-29973](https://insights.sbomify.com/CVE-2024-29973/): Command injection in NAS326 firmware (critical 9.8)
- [CVE-2024-29974](https://insights.sbomify.com/CVE-2024-29974/): File upload in NAS326 firmware (critical 9.8)
- [CVE-2023-35138](https://insights.sbomify.com/CVE-2023-35138/): Command injection in NAS326 firmware (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-27992 and fix it if it is affected.

What it is: CVE-2023-27992 is a critical command injection vulnerability in Zyxel NAS326 firmware, published on 19 Jun 2023. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: Yes. Attackers have exploited CVE-2023-27992 in the wild since at least 23 Jun 2023.

Affected product: Zyxel NAS326 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-2023-27992/ (Markdown: https://insights.sbomify.com/CVE-2023-27992/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-27992
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-27992
- OSV: https://osv.dev/vulnerability/CVE-2023-27992

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-27992/
Summaries are generated and may contain mistakes; the official description above is the record.