# CVE-2024-45396: Quicly assertion failures

> A remote attacker can trigger assertion failures in the Quicly library, causing a denial of service by crashing the application.

- **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:** 11 Oct 2024
- **Updated:** 15 Oct 2024
- **Also known as:** GHSA-mp3c-h5gg-mm6p

## What is CVE-2024-45396?

CVE-2024-45396 is a high-severity denial of service vulnerability in h2o quicly, published on 11 Oct 2024. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Quicly is an IETF QUIC protocol implementation. Quicly up to commtit d720707 is susceptible to a denial-of-service attack. A remote attacker can exploit these bugs to trigger an assertion failure that crashes process using quicly. The vulnerability is addressed with commit 2a95896104901589c495bc41460262e64ffcad5c.

Weakness: CWE-617 (Reachable Assertion)

## Which versions are affected by CVE-2024-45396?

It affects 1 product.


Products: Dena Quicly.

## How do I fix CVE-2024-45396?

No fix has been published for CVE-2024-45396 yet. Limit exposure of the affected software until one is available.

## Is CVE-2024-45396 being exploited?

There is no known exploitation of CVE-2024-45396 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2024-45396 and fix it if it is affected.

What it is: CVE-2024-45396 is a high-severity denial of service vulnerability in h2o quicly, published on 11 Oct 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 CVE-2024-45396 in the wild and no public exploit code.

Affected product: h2o quicly. 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-2024-45396/ (Markdown: https://insights.sbomify.com/CVE-2024-45396/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2024-45396
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-45396
- OSV: https://osv.dev/vulnerability/CVE-2024-45396

---
From sbomify Insights: https://insights.sbomify.com/CVE-2024-45396/
Summaries are generated and may contain mistakes; the official description above is the record.