# GHSA-w8gf-g2vq-j2f4: amphp/http-client Denial of Service via HTTP/2 CONTINUATION Frames

> An attacker can cause a denial of service via unbounded memory consumption in the amphp/http-client library by sending crafted HTTP/2 CONTINUATION frames.

- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 3 Apr 2024

## What is GHSA-w8gf-g2vq-j2f4?

GHSA-w8gf-g2vq-j2f4 is a denial of service vulnerability in amphp/http-client, published on 3 Apr 2024. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Early versions of `amphp/http-client` with HTTP/2 support (v4.0.0-rc10 to 4.0.0) will collect HTTP/2 `CONTINUATION` frames in an unbounded buffer and will not check the header size limit until it has received the `END_HEADERS` flag, resulting in an OOM crash. Later versions of `amphp/http-client` (v4.1.0-rc1 and up) depend on `amphp/http` for HTTP/2 processing and will therefore need an updated version of `amphp/http`, see [GHSA-qjfw-cvjf-f4fm](https://github.com/amphp/http/security/advisories/GHSA-qjfw-cvjf-f4fm).

## Acknowledgements

Thank you to [Bartek Nowotarski](https://nowotarski.info/) for reporting the vulnerability.

## Which versions are affected by GHSA-w8gf-g2vq-j2f4?

2 open source packages ship an affected version, including amphp/http-client.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `amphp/http-client` | Packagist | From 4.0.0-rc10 | 4.1.0-rc1 |
| `amphp/http-client` | Packagist | From 4.0.0-rc10 | 4.1.0-rc1 |

## How do I fix GHSA-w8gf-g2vq-j2f4?

Upgrade amphp/http-client to 4.1.0-rc1 or later.

## Is GHSA-w8gf-g2vq-j2f4 being exploited?

There is no known exploitation of GHSA-w8gf-g2vq-j2f4 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for GHSA-w8gf-g2vq-j2f4 and fix it if it is affected.

What it is: GHSA-w8gf-g2vq-j2f4 is a denial of service vulnerability in amphp/http-client, published on 3 Apr 2024. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of GHSA-w8gf-g2vq-j2f4 in the wild and no public exploit code.

Affected packages and fixed versions:
- amphp/http-client (Packagist): affected from 4.0.0-rc10; fixed in 4.1.0-rc1
- amphp/http-client (Packagist): affected from 4.0.0-rc10; fixed in 4.1.0-rc1

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/GHSA-w8gf-g2vq-j2f4/ (Markdown: https://insights.sbomify.com/GHSA-w8gf-g2vq-j2f4/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/GHSA-w8gf-g2vq-j2f4

---
From sbomify Insights: https://insights.sbomify.com/GHSA-w8gf-g2vq-j2f4/
Summaries are generated and may contain mistakes; the official description above is the record.