# CVE-2018-21111: Memory corruption in n/a

> Authenticated attackers can trigger a stack-based buffer overflow in NETGEAR routers, potentially leading to arbitrary code execution or privilege escalation.

- **Severity:** Medium 6.8 (`CVSS:3.0/AC:L/AV:A/A:H/C:H/I:H/PR:H/S:U/UI:N`)
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 22 Apr 2020
- **Updated:** 5 Aug 2024
- **Also known as:** GHSA-4r2q-5ff4-r8pg

## What is CVE-2018-21111?

CVE-2018-21111 is a medium-severity memory corruption vulnerability in Netgear D3600 Firmware, published on 22 Apr 2020. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

Certain NETGEAR devices are affected by a stack-based buffer overflow by an authenticated user. This affects D3600 before 1.0.0.75, D6000 before 1.0.0.75, D6100 before 1.0.0.60, R7800 before 1.0.2.52, R8900 before 1.0.4.2, R9000 before 1.0.4.2, WNDR3700v4 before 1.0.2.102, WNDR4300 before 1.0.2.104, WNDR4300v2 before 1.0.0.58, WNDR4500v3 before 1.0.0.58, and WNR2000v5 before 1.0.0.66.

Weakness: CWE-787 (Out-of-bounds Write)

## Which versions are affected by CVE-2018-21111?

It affects 10 products.


Products: Netgear D3600 Firmware, Netgear D6000 Firmware, Netgear D6100 Firmware, Netgear R7800 Firmware, Netgear R8900 Firmware, Netgear R9000 Firmware, Netgear Wndr3700 Firmware, Netgear Wndr4300 Firmware, Netgear Wndr4500 Firmware, Netgear Wnr2000 Firmware.

## How do I fix CVE-2018-21111?

No fix has been published for CVE-2018-21111 yet. Limit exposure of the affected software until one is available.

## Is CVE-2018-21111 being exploited?

There is no known exploitation of CVE-2018-21111 in the wild and no public exploit code.

## Other vulnerabilities in Netgear D3600 Firmware

- [CVE-2020-35799](https://insights.sbomify.com/CVE-2020-35799/): Memory corruption in n/a (high 8.8)
- [CVE-2018-21207](https://insights.sbomify.com/CVE-2018-21207/): Memory corruption in n/a (high 8.8)
- [CVE-2018-21210](https://insights.sbomify.com/CVE-2018-21210/): Memory corruption in n/a (high 8.8)
- [CVE-2018-21211](https://insights.sbomify.com/CVE-2018-21211/): Memory corruption in n/a (high 8.8)
- [CVE-2018-21212](https://insights.sbomify.com/CVE-2018-21212/): Memory corruption in n/a (high 8.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2018-21111 and fix it if it is affected.

What it is: CVE-2018-21111 is a medium-severity memory corruption vulnerability in Netgear D3600 Firmware, published on 22 Apr 2020. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2018-21111 in the wild and no public exploit code.

Affected product: Netgear D3600 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-2018-21111/ (Markdown: https://insights.sbomify.com/CVE-2018-21111/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2018-21111
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2018-21111
- OSV: https://osv.dev/vulnerability/CVE-2018-21111

---
From sbomify Insights: https://insights.sbomify.com/CVE-2018-21111/
Summaries are generated and may contain mistakes; the official description above is the record.