# CVE-2023-27989: Memory corruption in NR7101 firmware

> A remote authenticated attacker can cause denial of service on Zyxel NR7101 devices via a buffer overflow in the CGI program.

- **Severity:** Medium 6.5 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 5 Jun 2023
- **Updated:** 8 Jan 2025
- **Also known as:** GHSA-x86w-xv82-wrpx

## What is CVE-2023-27989?

CVE-2023-27989 is a medium-severity memory corruption vulnerability in Zyxel NR7101 firmware, published on 5 Jun 2023. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

A buffer overflow vulnerability in the CGI program of the Zyxel NR7101 firmware versions prior to  V1.00(ABUV.8)C0 could allow a remote authenticated attacker to cause denial of service (DoS) conditions by sending a crafted HTTP request to a vulnerable device.

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

## Which versions are affected by CVE-2023-27989?

It affects 4 products.


Products: Zyxel Lte7480-M804 Firmware, Zyxel Lte7490-M904 Firmware, Zyxel Nebula Nr7101 Firmware, Zyxel Nr7101 Firmware.

## How do I fix CVE-2023-27989?

No fix has been published for CVE-2023-27989 yet. Limit exposure of the affected software until one is available.

## Is CVE-2023-27989 being exploited?

There is no known exploitation of CVE-2023-27989 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-27989 and fix it if it is affected.

What it is: CVE-2023-27989 is a medium-severity memory corruption vulnerability in Zyxel NR7101 firmware, published on 5 Jun 2023. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2023-27989 in the wild and no public exploit code.

Affected product: Zyxel NR7101 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-2023-27989/ (Markdown: https://insights.sbomify.com/CVE-2023-27989/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-27989
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-27989
- OSV: https://osv.dev/vulnerability/CVE-2023-27989

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-27989/
Summaries are generated and may contain mistakes; the official description above is the record.