# CVE-2023-28769: Memory corruption in DX5401-B0 firmware

> Remote unauthenticated attackers can execute OS commands or cause denial-of-service via a buffer overflow in the Zyxel DX5401-B0 web server.

- **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:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 27 Apr 2023
- **Updated:** 31 Jan 2025
- **Also known as:** GHSA-xg39-26cw-gxj9

## What is CVE-2023-28769?

CVE-2023-28769 is a critical memory corruption vulnerability in Zyxel DX5401-B0 firmware, published on 27 Apr 2023. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

The buffer overflow vulnerability in the library “libclinkc.so” of the web server “zhttpd” in Zyxel DX5401-B0 firmware versions prior to V5.17(ABYO.1)C0 could allow a remote unauthenticated attacker to execute some OS commands or to cause denial-of-service (DoS) conditions on a vulnerable device.

Weakness: CWE-120 (Buffer Copy without Checking Size of Input)

## Which versions are affected by CVE-2023-28769?

It affects 1 product.


Products: Zyxel Dx5401-B0 Firmware.

## How do I fix CVE-2023-28769?

No fix has been published for CVE-2023-28769 yet. Limit exposure of the affected software until one is available.

## Is CVE-2023-28769 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2023-28769 exists.

Public exploit code:

- Zyxel Unauthenticated LAN Remote Code Execution (metasploit)

## Other vulnerabilities in Zyxel DX5401-B0 firmware

- [CVE-2023-28770](https://insights.sbomify.com/CVE-2023-28770/): Information disclosure in DX5401-B0 firmware (high 7.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-28769 and fix it if it is affected.

What it is: CVE-2023-28769 is a critical memory corruption vulnerability in Zyxel DX5401-B0 firmware, published on 27 Apr 2023. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2023-28769 exists.

Affected product: Zyxel DX5401-B0 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-2023-28769/ (Markdown: https://insights.sbomify.com/CVE-2023-28769/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-28769
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-28769
- OSV: https://osv.dev/vulnerability/CVE-2023-28769

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-28769/
Summaries are generated and may contain mistakes; the official description above is the record.