# CVE-2019-3560: Denial of service in fizz

> An attacker can cause a denial of service via an infinite loop in the Fizz TLS library due to improper buffer length calculation.

- **Severity:** High 7.5 (`CVSS:3.1/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:** No
- **Published:** 29 Apr 2019
- **Updated:** 13 Feb 2025
- **Also known as:** GHSA-q2rp-27fw-94mp

## What is CVE-2019-3560?

CVE-2019-3560 is a high-severity denial of service vulnerability in Facebook fizz, published on 29 Apr 2019. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

An improperly performed length calculation on a buffer in PlaintextRecordLayer could lead to an infinite loop and denial-of-service based on user input. This issue affected versions of fizz prior to v2019.03.04.00.

Weakness: CWE-131 (Incorrect Calculation of Buffer Size), CWE-835 (Loop with Unreachable Exit Condition)

## Which versions are affected by CVE-2019-3560?

It affects 1 product.


Products: Facebook Fizz.

## How do I fix CVE-2019-3560?

No fix has been published for CVE-2019-3560 yet. Limit exposure of the affected software until one is available.

## Is CVE-2019-3560 being exploited?

There is no known exploitation of CVE-2019-3560 in the wild and no public exploit code.

## Other vulnerabilities in Facebook fizz

- [CVE-2023-23759](https://insights.sbomify.com/CVE-2023-23759/): Denial of service in fizz (high 7.5)
- [CVE-2019-11924](https://insights.sbomify.com/CVE-2019-11924/): Denial of service in fizz (high 7.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2019-3560 and fix it if it is affected.

What it is: CVE-2019-3560 is a high-severity denial of service vulnerability in Facebook fizz, published on 29 Apr 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-2019-3560 in the wild and no public exploit code.

Affected product: Facebook fizz. 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-2019-3560/ (Markdown: https://insights.sbomify.com/CVE-2019-3560/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2019-3560
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2019-3560
- OSV: https://osv.dev/vulnerability/CVE-2019-3560

---
From sbomify Insights: https://insights.sbomify.com/CVE-2019-3560/
Summaries are generated and may contain mistakes; the official description above is the record.