# CVE-2025-6334: D-Link DIR-867 Query String strncpy stack-based overflow

> Remote attackers can trigger a stack-based buffer overflow in the query string handler of unsupported D-Link DIR-867 routers, potentially leading to code execution or denial of service.

- **Severity:** High 8.7 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P`)
- **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:** 20 Jun 2025
- **Updated:** 20 Jun 2025
- **Also known as:** GHSA-f3pg-qv5p-58pw

## What is CVE-2025-6334?

CVE-2025-6334 is a high-severity memory corruption vulnerability in D-Link DIR-867, published on 20 Jun 2025. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

A vulnerability has been found in D-Link DIR-867 1.0 and classified as critical. This vulnerability affects the function strncpy of the component Query String Handler. The manipulation leads to stack-based buffer overflow. The attack can be initiated remotely. The exploit has been disclosed to the public and may be used. This vulnerability only affects products that are no longer supported by the maintainer.

Weakness: CWE-121 (Stack-based Buffer Overflow), CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer)

## Which versions are affected by CVE-2025-6334?

It affects 1 product.


Products: Dlink Dir-867 Firmware.

## How do I fix CVE-2025-6334?

No fix has been published for CVE-2025-6334 yet. Limit exposure of the affected software until one is available.

## Is CVE-2025-6334 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2025-6334 exists.

## Other vulnerabilities in D-Link DIR-867

- [CVE-2023-24762](https://insights.sbomify.com/CVE-2023-24762/): Command injection in n/a (critical 9.8)
- [CVE-2022-41140](https://insights.sbomify.com/CVE-2022-41140/): Memory corruption in Multiple Routers (high 8.8)
- [CVE-2020-8863](https://insights.sbomify.com/CVE-2020-8863/): Auth bypass in Multiple Routers (high 8.8)
- [CVE-2020-8864](https://insights.sbomify.com/CVE-2020-8864/): Auth bypass in Multiple Routers (high 8.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-6334 and fix it if it is affected.

What it is: CVE-2025-6334 is a high-severity memory corruption vulnerability in D-Link DIR-867, published on 20 Jun 2025. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2025-6334 exists.

Affected product: D-Link DIR-867. 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-2025-6334/ (Markdown: https://insights.sbomify.com/CVE-2025-6334/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-6334
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-6334
- OSV: https://osv.dev/vulnerability/CVE-2025-6334

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-6334/
Summaries are generated and may contain mistakes; the official description above is the record.