# CVE-2019-5599: Denial of service in FreeBSD

> An attacker can cause resource exhaustion and denial of service in FreeBSD by exploiting a bug in the non-default RACK TCP stack.

- **Severity:** High 7.5 (`CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 2 Jul 2019
- **Updated:** 4 Aug 2024
- **Also known as:** GHSA-2c7c-f76h-r8hx

## What is CVE-2019-5599?

CVE-2019-5599 is a high-severity denial of service vulnerability in Freebsd Freebsd, published on 2 Jul 2019. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

In FreeBSD 12.0-STABLE before r349197 and 12.0-RELEASE before 12.0-RELEASE-p6, a bug in the non-default RACK TCP stack can allow an attacker to cause several linked lists to grow unbounded and cause an expensive list traversal on every packet being processed, leading to resource exhaustion and a denial of service.

Weakness: CWE-770 (Allocation of Resources Without Limits or Throttling)

## Which versions are affected by CVE-2019-5599?

It affects 1 product.


Products: Freebsd Freebsd.

## How do I fix CVE-2019-5599?

Apply the vendor's patch.

## Is CVE-2019-5599 being exploited?

There is no known exploitation of CVE-2019-5599 in the wild and no public exploit code.

## Other vulnerabilities in Freebsd Freebsd

- [CVE-2018-17160](https://insights.sbomify.com/CVE-2018-17160/): Memory corruption in FreeBSD (critical 10.0)
- [CVE-2014-3954](https://insights.sbomify.com/CVE-2014-3954/): Memory corruption in n/a (critical 10.0)
- [CVE-2006-4304](https://insights.sbomify.com/CVE-2006-4304/): Memory corruption in n/a (critical 10.0)
- [CVE-2006-0226](https://insights.sbomify.com/CVE-2006-0226/): Integer overflow in n/a (critical 10.0)
- [CVE-2004-0002](https://insights.sbomify.com/CVE-2004-0002/): Denial of service in n/a (critical 10.0)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2019-5599 and fix it if it is affected.

What it is: CVE-2019-5599 is a high-severity denial of service vulnerability in Freebsd Freebsd, published on 2 Jul 2019. 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-2019-5599 in the wild and no public exploit code.

Affected product: Freebsd Freebsd. 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-2019-5599/ (Markdown: https://insights.sbomify.com/CVE-2019-5599/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2019-5599
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2019-5599
- OSV: https://osv.dev/vulnerability/CVE-2019-5599

---
From sbomify Insights: https://insights.sbomify.com/CVE-2019-5599/
Summaries are generated and may contain mistakes; the official description above is the record.