# CVE-2019-9514: Some HTTP/2 implementations are vulnerable to a reset flood, potentially leading to a denial of service

> Attackers can cause denial of service in HTTP/2 implementations by flooding streams with invalid requests, consuming excessive memory and CPU resources.

- **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:** 13 Aug 2019
- **Updated:** 4 Aug 2024
- **Also known as:** ALPINE-CVE-2019-9514, AZL-38389, CLEANSTART-2025-AF65508, CLEANSTART-2026-QQ59156, CLEANSTART-2026-YV80778, CVE-2019-14990, DEBIAN-CVE-2019-9514, GHSA-8r5v-vm4m-4g25, RUSTSEC-2024-0003, UBUNTU-CVE-2019-9514

## What is CVE-2019-9514?

CVE-2019-9514 is a high-severity denial of service vulnerability in Apache Traffic Server, published on 13 Aug 2019. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Some HTTP/2 implementations are vulnerable to a reset flood, potentially leading to a denial of service. The attacker opens a number of streams and sends an invalid request over each stream that should solicit a stream of RST_STREAM frames from the peer. Depending on how the peer queues the RST_STREAM frames, this can consume excess memory, CPU, or both.

Weakness: CWE-770 (Allocation of Resources Without Limits or Throttling), CWE-400 (Uncontrolled Resource Consumption)

## Which versions are affected by CVE-2019-9514?

5 open source packages ship an affected version, including h2. It affects 28 products.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `h2` | crates.io | All versions | 0.3.24 |
| `h2` | crates.io | All versions | 0.3.24 |
| `h2` | crates.io | From 0.0.0-0 | 0.3.24, 0.4.2 |
| `h2` | crates.io | From 0.4.0 | 0.4.2 |
| `h2` | crates.io | From 0.4.0 | 0.4.2 |

Products: Apache Traffic Server, Apple Swiftnio, Canonical Ubuntu Linux, Debian Debian Linux, F5 Big-Ip Local Traffic Manager, Fedoraproject Fedora, Mcafee Web Gateway, Netapp Cloud Insights, Netapp Trident, Nodejs Node.js, Opensuse Leap, Oracle Graalvm, Redhat Developer Tools, Redhat Enterprise Linux, Redhat Enterprise Linux Eus, Redhat Enterprise Linux Server, Redhat Enterprise Linux Workstation, Redhat Jboss Core Services, Redhat Jboss Enterprise Application Platform, Redhat Openshift Container Platform and 8 more.

## How do I fix CVE-2019-9514?

Upgrade h2 to a fixed version for your release line: 0.3.24 or 0.4.2.

## Is CVE-2019-9514 being exploited?

There is no known exploitation of CVE-2019-9514 in the wild and no public exploit code.

## Other vulnerabilities in Apache Traffic Server

- [CVE-2014-3525](https://insights.sbomify.com/CVE-2014-3525/): Other in n/a (critical 10.0)
- [CVE-2021-43082](https://insights.sbomify.com/CVE-2021-43082/): heap-buffer-overflow with stats-over-http plugin (critical 9.8)
- [CVE-2021-35474](https://insights.sbomify.com/CVE-2021-35474/): Dynamic stack buffer overflow in cachekey plugin (critical 9.8)
- [CVE-2019-17559](https://insights.sbomify.com/CVE-2019-17559/): Other in Apache Traffic Server (critical 9.8)
- [CVE-2019-17565](https://insights.sbomify.com/CVE-2019-17565/): Other in Apache Traffic Server (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2019-9514 and fix it if it is affected.

What it is: CVE-2019-9514 is a high-severity denial of service vulnerability in Apache Traffic Server, published on 13 Aug 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-2019-9514 in the wild and no public exploit code.

Affected packages and fixed versions:
- h2 (crates.io): affected all versions; fixed in 0.3.24
- h2 (crates.io): affected all versions; fixed in 0.3.24
- h2 (crates.io): affected from 0.0.0-0; fixed in 0.3.24, 0.4.2
- h2 (crates.io): affected from 0.4.0; fixed in 0.4.2
- h2 (crates.io): affected from 0.4.0; fixed in 0.4.2

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-2019-9514/ (Markdown: https://insights.sbomify.com/CVE-2019-9514/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2019-9514
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2019-9514
- OSV: https://osv.dev/vulnerability/CVE-2019-9514

---
From sbomify Insights: https://insights.sbomify.com/CVE-2019-9514/
Summaries are generated and may contain mistakes; the official description above is the record.