# CVE-2023-6180: Resource exhaustion via memory leak in tokio-boring

> An attacker can cause resource exhaustion and denial of service by triggering a memory leak in the tokio-boring TLS library during connection handling.

- **Severity:** Medium 5.3 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 5 Dec 2023
- **Updated:** 2 Aug 2024
- **Also known as:** GHSA-pjrj-h4fg-6gm4

## What is CVE-2023-6180?

CVE-2023-6180 is a medium-severity denial of service vulnerability in Cloudflare tokio-boring, published on 5 Dec 2023. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

The tokio-boring library in version 4.0.0 is affected by a memory leak issue that can lead to excessive resource consumption and potential DoS by resource exhaustion. The set_ex_data function used by the library did not deallocate memory used by pre-existing data in memory each time after completing a TLS connection causing the program to consume more resources with each new connection.

Weakness: CWE-401 (Missing Release of Memory after Effective Lifetime), CWE-404 (Improper Resource Shutdown or Release), CWE-400 (Uncontrolled Resource Consumption)

## Which versions are affected by CVE-2023-6180?

2 open source packages ship an affected version, including tokio-boring. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `tokio-boring` | crates.io | From 4.0.0 | 4.1.0 |
| `tokio-boring` | crates.io | From 4.0.0 | 4.1.0 |

Products: Cloudflare Boring.

## How do I fix CVE-2023-6180?

Upgrade tokio-boring to 4.1.0 or later.

## Is CVE-2023-6180 being exploited?

There is no known exploitation of CVE-2023-6180 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-6180 and fix it if it is affected.

What it is: CVE-2023-6180 is a medium-severity denial of service vulnerability in Cloudflare tokio-boring, published on 5 Dec 2023. 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-2023-6180 in the wild and no public exploit code.

Affected packages and fixed versions:
- tokio-boring (crates.io): affected from 4.0.0; fixed in 4.1.0
- tokio-boring (crates.io): affected from 4.0.0; fixed in 4.1.0

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-2023-6180/ (Markdown: https://insights.sbomify.com/CVE-2023-6180/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-6180
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-6180
- OSV: https://osv.dev/vulnerability/CVE-2023-6180

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-6180/
Summaries are generated and may contain mistakes; the official description above is the record.