# CVE-2012-4435: Denial of service in n/a

> Remote authenticated users can crash the fwknop server by sending a long IP address, causing a denial of service.

- **Severity:** Medium 4.0 (`AV:N/AC:L/Au:S/C:N/I:N/A:P`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 22 Oct 2012
- **Updated:** 6 Aug 2024
- **Also known as:** DEBIAN-CVE-2012-4435, GHSA-jvjc-qf53-pgj7

## What is CVE-2012-4435?

CVE-2012-4435 is a medium-severity denial of service vulnerability in n/a, published on 22 Oct 2012. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

fwknop before 2.0.3 does not properly validate IP addresses, which allows remote authenticated users to cause a denial of service (server crash) via a long IP address.

Weakness: CWE-20 (Improper Input Validation)

## Which versions are affected by CVE-2012-4435?

It affects 1 product.


Products: Cipherdyne Fwknop.

## How do I fix CVE-2012-4435?

Upgrade to a fixed version.

## Is CVE-2012-4435 being exploited?

There is no known exploitation of CVE-2012-4435 in the wild and no public exploit code.

## Other vulnerabilities in n/a

- [CVE-2012-4434](https://insights.sbomify.com/CVE-2012-4434/): fwknop before 2.0.3 allow remote authenticated users to cause a denial of service (server crash) or possibly execute arbitrary code. (high 8.8)
- [CVE-2012-4436](https://insights.sbomify.com/CVE-2012-4436/): Memory corruption in n/a (medium 4.4)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2012-4435 and fix it if it is affected.

What it is: CVE-2012-4435 is a medium-severity denial of service vulnerability in n/a, published on 22 Oct 2012. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2012-4435 in the wild and no public exploit code.

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-2012-4435/ (Markdown: https://insights.sbomify.com/CVE-2012-4435/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2012-4435
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2012-4435
- OSV: https://osv.dev/vulnerability/CVE-2012-4435

---
From sbomify Insights: https://insights.sbomify.com/CVE-2012-4435/
Summaries are generated and may contain mistakes; the official description above is the record.