# CVE-2018-12541: Excessive memory allocation

> Attackers can cause memory exhaustion and denial of service by sending large WebSocket upgrade requests to applications using vulnerable Eclipse Vert.x versions.

- **Severity:** Medium 6.5 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H`)
- **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:** 10 Oct 2018
- **Updated:** 5 Aug 2024
- **Also known as:** GHSA-45xm-v8gq-7jqx

## What is CVE-2018-12541?

CVE-2018-12541 is a medium-severity denial of service vulnerability in The Eclipse Foundation Eclipse Vert.x, published on 10 Oct 2018. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

In version from 3.0.0 to 3.5.3 of Eclipse Vert.x, the WebSocket HTTP upgrade implementation buffers the full http request before doing the handshake, holding the entire request body in memory. There should be a reasonnable limit (8192 bytes) above which the WebSocket gets an HTTP response with the 413 status code and the connection gets closed.

Weakness: CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer), CWE-789 (Memory Allocation with Excessive Size Value)

## Which versions are affected by CVE-2018-12541?

2 open source packages ship an affected version, including io.vertx:vertx-core. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `io.vertx:vertx-core` | Maven | From 3.0.0 | 3.5.4 |
| `io.vertx:vertx-core` | Maven | From 3.0.0 | 3.5.4 |

Products: Eclipse Vert.x.

## How do I fix CVE-2018-12541?

Upgrade io.vertx:vertx-core to 3.5.4 or later.

## Is CVE-2018-12541 being exploited?

There is no known exploitation of CVE-2018-12541 in the wild and no public exploit code.

## Other vulnerabilities in The Eclipse Foundation Eclipse Vert.x

- [CVE-2019-17640](https://insights.sbomify.com/CVE-2019-17640/): Path Traversal in Eclipse Vert (critical 9.8)
- [CVE-2018-12542](https://insights.sbomify.com/CVE-2018-12542/): Eclipse Vert.x does not properly neutralize '' (forward slashes) sequences that can resolve to an external location (critical 9.8)
- [CVE-2018-12544](https://insights.sbomify.com/CVE-2018-12544/): Moderate severity vulnerability that affects io.vertx:vertx-core (critical 9.8)
- [CVE-2026-102469](https://insights.sbomify.com/CVE-2026-102469/): Deserialization in Eclipse Vert.x (critical 9.2)
- [CVE-2018-12540](https://insights.sbomify.com/CVE-2018-12540/): High severity vulnerability that affects io.vertx:vertx-web (high 8.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2018-12541 and fix it if it is affected.

What it is: CVE-2018-12541 is a medium-severity denial of service vulnerability in The Eclipse Foundation Eclipse Vert.x, published on 10 Oct 2018. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2018-12541 in the wild and no public exploit code.

Affected packages and fixed versions:
- io.vertx:vertx-core (Maven): affected from 3.0.0; fixed in 3.5.4
- io.vertx:vertx-core (Maven): affected from 3.0.0; fixed in 3.5.4

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-2018-12541/ (Markdown: https://insights.sbomify.com/CVE-2018-12541/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2018-12541
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2018-12541
- OSV: https://osv.dev/vulnerability/CVE-2018-12541

---
From sbomify Insights: https://insights.sbomify.com/CVE-2018-12541/
Summaries are generated and may contain mistakes; the official description above is the record.