# CVE-2021-27114: Memory corruption in n/a

> A stack-based buffer overflow in the D-Link DIR-816 router allows attackers to overwrite the return address and potentially execute arbitrary code.

- **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:** 14 Apr 2021
- **Updated:** 3 Aug 2024
- **Also known as:** GHSA-h8c7-76x8-mr96

## What is CVE-2021-27114?

CVE-2021-27114 is a critical memory corruption vulnerability in Dlink Dir-816 Firmware, published on 14 Apr 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

An issue was discovered in D-Link DIR-816 A2 1.10 B05 devices. Within the handler function of the /goform/addassignment route, a very long text entry for the"'s_ip" and "s_mac" fields could lead to a Stack-Based Buffer Overflow and overwrite the return address.

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

## Which versions are affected by CVE-2021-27114?

It affects 1 product.


Products: Dlink Dir-816 Firmware.

## How do I fix CVE-2021-27114?

No fix has been published for CVE-2021-27114 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-27114 being exploited?

There is no known exploitation of CVE-2021-27114 in the wild and no public exploit code.

## Other vulnerabilities in Dlink Dir-816 Firmware

- [CVE-2025-45931](https://insights.sbomify.com/CVE-2025-45931/): Command injection in n/a (critical 9.8)
- [CVE-2024-57684](https://insights.sbomify.com/CVE-2024-57684/): Missing authorization in n/a (critical 9.8)
- [CVE-2023-24331](https://insights.sbomify.com/CVE-2023-24331/): Command injection in n/a (critical 9.8)
- [CVE-2024-24321](https://insights.sbomify.com/CVE-2024-24321/): Command injection in n/a (critical 9.8)
- [CVE-2023-39637](https://insights.sbomify.com/CVE-2023-39637/): Command injection in n/a (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-27114 and fix it if it is affected.

What it is: CVE-2021-27114 is a critical memory corruption vulnerability in Dlink Dir-816 Firmware, published on 14 Apr 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2021-27114 in the wild and no public exploit code.

Affected product: Dlink Dir-816 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-2021-27114/ (Markdown: https://insights.sbomify.com/CVE-2021-27114/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-27114
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-27114
- OSV: https://osv.dev/vulnerability/CVE-2021-27114

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-27114/
Summaries are generated and may contain mistakes; the official description above is the record.