# CVE-2025-4321: DoS in RS9116W-WiSeConnect L2CAP protocol due to reception of malformed packets

> Attackers can cause a denial of service in RS9116W Bluetooth devices by sending malformed L2CAP packets, requiring a hard reset to recover.

- **Severity:** High 7.1 (`CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N`)
- **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:** 17 Nov 2025
- **Updated:** 17 Nov 2025
- **Also known as:** GHSA-5hr4-696x-x4hr

## What is CVE-2025-4321?

CVE-2025-4321 is a high-severity denial of service vulnerability in silabs.com RS9116W, published on 17 Nov 2025. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

In a Bluetooth device, using RS9116-WiseConnect SDK experiences a Denial of Service, if it receives malformed L2CAP packets, only hard reset will bring the device to normal operation

Weakness: CWE-617 (Reachable Assertion), CWE-240 (Improper Handling of Inconsistent Structural Elements)

## Which versions are affected by CVE-2025-4321?


## How do I fix CVE-2025-4321?

No fix has been published for CVE-2025-4321 yet. Limit exposure of the affected software until one is available.

## Is CVE-2025-4321 being exploited?

There is no known exploitation of CVE-2025-4321 in the wild and no public exploit code.

Public exploit code:

- Enterprise Patch Management Scenario – "Critical Patch Response for Financial Systems" Background You are the IT Administrator for a multinational financial services company that operates across India, the US, and Europe. A critical vulnerability (Ex: CVE-2025-4321) -  must identify, approve, and prepare for patch deployment within 48 hours.  (github_poc): https://github.com/Salman-Sec/Patch-management-

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-4321 and fix it if it is affected.

What it is: CVE-2025-4321 is a high-severity denial of service vulnerability in silabs.com RS9116W, published on 17 Nov 2025. 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-2025-4321 in the wild and no public exploit code.

Affected product: silabs.com RS9116W. 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-2025-4321/ (Markdown: https://insights.sbomify.com/CVE-2025-4321/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-4321
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-4321
- OSV: https://osv.dev/vulnerability/CVE-2025-4321

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-4321/
Summaries are generated and may contain mistakes; the official description above is the record.