CVE-2022-29223: Buffer overflow on HUB descriptor in Azure RTOS USBX

Severity: critical (CVSS 9.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 1.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2022-05-24 · updated 2026-06-17
Weakness: CWE-120

Description

Azure RTOS USBX is a USB host, device, and on-the-go (OTG) embedded stack. In versions prior to 6.1.10, an attacker can cause a buffer overflow by providing the Azure RTOS USBX host stack a HUB descriptor with `bNbPorts` set to a value greater than `UX_MAX_TT` which defaults to 8. For a `bNbPorts` value of 255, the implementation of `ux_host_class_hub_descriptor_get` function will modify the contents of `hub` -> `ux_host_class_hub_device` -> `ux_device_hub_tt` array violating the end boundary by 255 - `UX_MAX_TT` items. The USB host stack needs to validate the number of ports reported by the hub, and if the value is larger than UX_MAX_TT, USB stack needs to reject the request. This fix has been included in USBX release 6.1.10.

Affected products

azure-rtos usbx: before 6.1.10 — fixed in 6.1.10

How to fix

Upgrade to a fixed version: azure-rtos usbx 6.1.10. Check the vendor advisory for mitigations.

References

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