# CVE-2024-1300: Io.vertx:vertx-core: memory leak when a tcp server is configured with tls and sni support

> Attackers can cause a denial of service by exhausting memory in Vert.x TCP servers using TLS and SNI with unknown server names.

- **Severity:** Medium 5.4 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:L`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 2 Apr 2024
- **Updated:** 23 Sep 2026
- **Also known as:** GHSA-9ph3-v2vh-3qx7

## What is CVE-2024-1300?

CVE-2024-1300 is a medium-severity denial of service vulnerability in Red Hat A-MQ Clients 2, published on 2 Apr 2024. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

A vulnerability in the Eclipse Vert.x toolkit causes a memory leak in TCP servers configured with TLS and SNI support. When processing an unknown SNI server name assigned the default certificate instead of a mapped certificate, the SSL context is erroneously cached in the server name map, leading to memory exhaustion. This flaw allows attackers to send TLS client hello messages with fake server names, triggering a JVM out-of-memory error.

Weakness: CWE-772 (Missing Release of Resource after Effective Lifetime)

## Which versions are affected by CVE-2024-1300?

4 open source packages ship an affected version, including io.vertx:vertx-core.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `io.vertx:vertx-core` | Maven | From 4.3.4 | 4.4.8 |
| `io.vertx:vertx-core` | Maven | From 4.3.4 | 4.4.8 |
| `io.vertx:vertx-core` | Maven | From 4.5.0 | 4.5.3 |
| `io.vertx:vertx-core` | Maven | From 4.5.0 | 4.5.3 |

## How do I fix CVE-2024-1300?

Upgrade io.vertx:vertx-core to a fixed version for your release line: 4.4.8 or 4.5.3.

## Is CVE-2024-1300 being exploited?

There is no known exploitation of CVE-2024-1300 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2024-1300 and fix it if it is affected.

What it is: CVE-2024-1300 is a medium-severity denial of service vulnerability in Red Hat A-MQ Clients 2, published on 2 Apr 2024. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2024-1300 in the wild and no public exploit code.

Affected packages and fixed versions:
- io.vertx:vertx-core (Maven): affected from 4.3.4; fixed in 4.4.8
- io.vertx:vertx-core (Maven): affected from 4.3.4; fixed in 4.4.8
- io.vertx:vertx-core (Maven): affected from 4.5.0; fixed in 4.5.3
- io.vertx:vertx-core (Maven): affected from 4.5.0; fixed in 4.5.3

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-2024-1300/ (Markdown: https://insights.sbomify.com/CVE-2024-1300/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2024-1300
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-1300
- OSV: https://osv.dev/vulnerability/CVE-2024-1300

---
From sbomify Insights: https://insights.sbomify.com/CVE-2024-1300/
Summaries are generated and may contain mistakes; the official description above is the record.