# CVE-2022-36063: USBX Host CDC ECM integer underflow with buffer overflow

> An integer underflow in Azure RTOS USBX CDC ECM host allows remote code execution or denial of service via malicious MAC address descriptors.

- **Severity:** High 7.6 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/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:** No
- **Published:** 10 Oct 2022
- **Updated:** 22 Apr 2025
- **Also known as:** GHSA-chpp-5fv9-6368

## What is CVE-2022-36063?

CVE-2022-36063 is a high-severity vulnerability in azure-rtos usbx, published on 10 Oct 2022. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

Azure RTOS USBx is a USB host, device, and on-the-go (OTG) embedded stack, fully integrated with Azure RTOS ThreadX and available for all Azure RTOS ThreadX–supported processors. Azure RTOS USBX implementation of host support for USB CDC ECM includes an integer underflow and a buffer overflow in the `_ux_host_class_cdc_ecm_mac_address_get` function which may be potentially exploited to achieve remote code execution or denial of service. Setting mac address string descriptor length to a `0` or `1` allows an attacker to introduce an integer underflow followed (string_length) by a buffer overflow of the `cdc_ecm -> ux_host_class_cdc_ecm_node_id` array. This may allow one to redirect the code execution flow or introduce a denial of service. The fix has been included in USBX release [6.1.12](https://github.com/azure-rtos/usbx/releases/tag/v6.1.12_rel). Improved mac address string descriptor length validation to check for unexpectedly small values may be used as a workaround.

Weakness: CWE-1284 (Improper Validation of Specified Quantity in Input), CWE-191 (Integer Underflow (Wrap or Wraparound)), CWE-121 (Stack-based Buffer Overflow)

## Which versions are affected by CVE-2022-36063?

It affects 1 product.


Products: Eclipse Threadx Usbx.

## How do I fix CVE-2022-36063?

No fix has been published for CVE-2022-36063 yet. Limit exposure of the affected software until one is available.

## Is CVE-2022-36063 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2022-36063 exists.

## Other vulnerabilities in azure-rtos usbx

- [CVE-2022-29246](https://insights.sbomify.com/CVE-2022-29246/): Potential buffer overflow in function DFU upload in Azure RTOS USBX (critical 9.8)
- [CVE-2022-39293](https://insights.sbomify.com/CVE-2022-39293/): Azure RTOS USBX Host PIMA vulnerable to read integer underflow with buffer overflow (high 8.6)
- [CVE-2022-29223](https://insights.sbomify.com/CVE-2022-29223/): Buffer overflow on HUB descriptor in Azure RTOS USBX (high 7.5)
- [CVE-2023-48695](https://insights.sbomify.com/CVE-2023-48695/): Azure RTOS USBX Remote Code Execution Vulnerability (high 7.2)
- [CVE-2023-48694](https://insights.sbomify.com/CVE-2023-48694/): Azure RTOS USBX Remote Code Execution Vulnerability (medium 6.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2022-36063 and fix it if it is affected.

What it is: CVE-2022-36063 is a high-severity vulnerability in azure-rtos usbx, published on 10 Oct 2022. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2022-36063 exists.

Affected product: azure-rtos usbx. 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-2022-36063/ (Markdown: https://insights.sbomify.com/CVE-2022-36063/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2022-36063
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2022-36063
- OSV: https://osv.dev/vulnerability/CVE-2022-36063

---
From sbomify Insights: https://insights.sbomify.com/CVE-2022-36063/
Summaries are generated and may contain mistakes; the official description above is the record.