# CVE-2019-9503: Broadcom brcmfmac driver is vulnerable to a frame validation bypass

> Remote attackers can bypass frame validation in the Broadcom brcmfmac driver via USB, potentially executing arbitrary code or causing denial of service.

- **Severity:** High 7.9 (`CVSS:3.1/AV:A/AC:H/PR:N/UI:R/S:C/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 16 Jan 2020
- **Updated:** 4 Aug 2024
- **Also known as:** CVE-2019-9466, DEBIAN-CVE-2019-9503, GHSA-6g85-84jx-q393, UBUNTU-CVE-2019-9503

## What is CVE-2019-9503?

CVE-2019-9503 is a high-severity vulnerability in Redhat Enterprise Linux, published on 16 Jan 2020. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.

### Official description

The Broadcom brcmfmac WiFi driver prior to commit a4176ec356c73a46c07c181c6d04039fafa34a9f is vulnerable to a frame validation bypass. If the brcmfmac driver receives a firmware event frame from a remote source, the is_wlc_event_frame function will cause this frame to be discarded and unprocessed. If the driver receives the firmware event frame from the host, the appropriate handler is called. This frame validation can be bypassed if the bus used is USB (for instance by a wifi dongle). This can allow firmware event frames from a remote source to be processed. In the worst case scenario, by sending specially-crafted WiFi packets, a remote, unauthenticated attacker may be able to execute arbitrary code on a vulnerable system. More typically, this vulnerability will result in denial-of-service conditions.

Weakness: CWE-20 (Improper Input Validation)

## Which versions are affected by CVE-2019-9503?

It affects 2 products.


Products: Broadcom Brcmfmac Driver, Redhat Enterprise Linux.

## How do I fix CVE-2019-9503?

Apply the vendor's patch.

## Is CVE-2019-9503 being exploited?

There is no known exploitation of CVE-2019-9503 in the wild and no public exploit code.

## Other vulnerabilities in Redhat Enterprise Linux

- [CVE-2019-9500](https://insights.sbomify.com/CVE-2019-9500/): Broadcom brcmfmac driver is vulnerable to a heap buffer overflow (high 7.9)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2019-9503 and fix it if it is affected.

What it is: CVE-2019-9503 is a high-severity vulnerability in Redhat Enterprise Linux, published on 16 Jan 2020. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2019-9503 in the wild and no public exploit code.

Affected product: Redhat Enterprise Linux. 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-2019-9503/ (Markdown: https://insights.sbomify.com/CVE-2019-9503/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2019-9503
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2019-9503
- OSV: https://osv.dev/vulnerability/CVE-2019-9503

---
From sbomify Insights: https://insights.sbomify.com/CVE-2019-9503/
Summaries are generated and may contain mistakes; the official description above is the record.