# CVE-2024-4785: BT: Missing Check in LL_CONNECTION_UPDATE_IND Packet Leads to Division by Zero

> A missing check in Zephyr RTOS Bluetooth handling allows attackers to cause a division by zero error, resulting in a denial of service.

- **Severity:** High 7.6 (`CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 19 Aug 2024
- **Updated:** 17 Sep 2025

## What is CVE-2024-4785?

CVE-2024-4785 is a high-severity denial of service vulnerability in Zephyrproject Zephyr, published on 19 Aug 2024. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

BT: Missing Check in LL_CONNECTION_UPDATE_IND Packet Leads to Division by Zero

Weakness: CWE-369 (Divide By Zero)

## Which versions are affected by CVE-2024-4785?

It affects 1 product.


Products: Zephyrproject Zephyr.

## How do I fix CVE-2024-4785?

No fix has been published for CVE-2024-4785 yet. Limit exposure of the affected software until one is available.

## Is CVE-2024-4785 being exploited?

There is no known exploitation of CVE-2024-4785 in the wild and no public exploit code.

## Other vulnerabilities in Zephyrproject Zephyr

- [CVE-2026-5067](https://insights.sbomify.com/CVE-2026-5067/): Out-of-bounds read/write in HTTP WebSocket upgrade via non-null-terminated Sec-WebSocket-Key (critical 9.8)
- [CVE-2022-3806](https://insights.sbomify.com/CVE-2022-3806/): Bluetooth HCI Error Handling Double Free (critical 9.8)
- [CVE-2017-14199](https://insights.sbomify.com/CVE-2017-14199/): Memory corruption in getaddrinfo (critical 9.8)
- [CVE-2018-1000800](https://insights.sbomify.com/CVE-2018-1000800/): Null dereference in n/a (critical 9.8)
- [CVE-2021-3329](https://insights.sbomify.com/CVE-2021-3329/): DOS: Incorrect handling of the initial HCI ACL_MTU handshake packet leads to crash of bluetooth host layer (critical 9.6)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2024-4785 and fix it if it is affected.

What it is: CVE-2024-4785 is a high-severity denial of service vulnerability in Zephyrproject Zephyr, published on 19 Aug 2024. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2024-4785 in the wild and no public exploit code.

Affected product: Zephyrproject Zephyr. 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-2024-4785/ (Markdown: https://insights.sbomify.com/CVE-2024-4785/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2024-4785
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-4785
- OSV: https://osv.dev/vulnerability/CVE-2024-4785

---
From sbomify Insights: https://insights.sbomify.com/CVE-2024-4785/
Summaries are generated and may contain mistakes; the official description above is the record.