# CVE-2007-3947: Denial of service in n/a

> Remote attackers can crash the lighttpd web server by sending HTTP requests with duplicate headers, causing a denial of service.

- **Severity:** Medium 5.8 (`AV:N/AC:M/Au:N/C:P/I:N/A:P`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 24 Jul 2007
- **Updated:** 7 Aug 2024
- **Also known as:** CVE-2007-2841, DEBIAN-CVE-2007-3947, GHSA-x97h-9f4h-rj28

## What is CVE-2007-3947?

CVE-2007-3947 is a medium-severity denial of service vulnerability in n/a, published on 24 Jul 2007. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

request.c in lighttpd 1.4.15 allows remote attackers to cause a denial of service (daemon crash) by sending an HTTP request with duplicate headers, as demonstrated by a request containing two Location header lines, which results in a segmentation fault.

## Which versions are affected by CVE-2007-3947?

It affects 1 product.


Products: Lighttpd Lighttpd.

## How do I fix CVE-2007-3947?

Upgrade to a fixed version.

## Is CVE-2007-3947 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2007-3947 exists.

Public exploit code:

- Lighttpd 1.4.15 - Multiple Code Execution / Denial of Service / Information Disclosure Vulnerabilities (exploitdb)

## Other vulnerabilities in n/a

- [CVE-2019-11072](https://insights.sbomify.com/CVE-2019-11072/): Integer overflow in n/a (critical 9.8)
- [CVE-2007-3949](https://insights.sbomify.com/CVE-2007-3949/): Security feature bypass in n/a (high 8.3)
- [CVE-2007-1870](https://insights.sbomify.com/CVE-2007-1870/): Null dereference in n/a (high 7.8)
- [CVE-2022-30780](https://insights.sbomify.com/CVE-2022-30780/): Denial of service in n/a (high 7.5)
- [CVE-2025-12642](https://insights.sbomify.com/CVE-2025-12642/): HTTP Header Smuggling via Trailer Merge (medium 6.9)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2007-3947 and fix it if it is affected.

What it is: CVE-2007-3947 is a medium-severity denial of service vulnerability in n/a, published on 24 Jul 2007. 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-2007-3947 exists.

Affected product: n/a. 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-2007-3947/ (Markdown: https://insights.sbomify.com/CVE-2007-3947/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2007-3947
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2007-3947
- OSV: https://osv.dev/vulnerability/CVE-2007-3947

---
From sbomify Insights: https://insights.sbomify.com/CVE-2007-3947/
Summaries are generated and may contain mistakes; the official description above is the record.