Azure RTOS USBX Host PIMA vulnerable to read integer underflow with buffer overflow
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Code execution
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- Fixed
Attack profile from CVSS 3.1 · NVD. Fix status from CNA. Impact type from CWE-191 and the CVSS impact.
Summary
Azure RTOS USBX is a high-performance USB host, device, and on-the-go (OTG) embedded stack, that is fully integrated with Azure RTOS ThreadX. The case is, in [_ux_host_class_pima_read](https://github.com/azure-rtos/usbx/blob/master/common/usbx_host_classes/src/ux_host_class_pima_read.c), there is data length from device response, returned in the very first packet, and read by [L165 code](https://github.com/azure-rtos/usbx/blob/082fd9db09a3669eca3358f10b8837a5c1635c0b/common/usbx_host_classes/src/ux_host_class_pima_read.c#L165), as header_length. Then in [L178 code](https://github.com/azure-rtos/usbx/blob/082fd9db09a3669eca3358f10b8837a5c1635c0b/common/usbx_host_classes/src/ux_host_class_pima_read.c#L178), there is a “if” branch, which check the expression of “(header_length - UX_HOST_CLASS_PIMA_DATA_HEADER_SIZE) > data_length” where if header_length is smaller than UX_HOST_CLASS_PIMA_DATA_HEADER_SIZE, calculation could overflow and then [L182 code](https://github.com/azure-rtos/usbx/blob/082fd9db09a3669eca3358f10b8837a5c1635c0b/common/usbx_host_classes/src/ux_host_class_pima_read.c#L182) the calculation of data_length is also overflow, this way the later [while loop start from L192](https://github.com/azure-rtos/usbx/blob/082fd9db09a3669eca3358f10b8837a5c1635c0b/common/usbx_host_classes/src/ux_host_class_pima_read.c#L192) can move data_pointer to unexpected address and cause write buffer overflow. The fix has been included in USBX release [6.1.12](https://github.com/azure-rtos/usbx/releases/tag/v6.1.12_rel). The following can be used as a workaround: Add check of `header_length`: 1. It must be greater than `UX_HOST_CLASS_PIMA_DATA_HEADER_SIZE`. 1. It should be greater or equal to the current returned data length (`transfer_request -> ux_transfer_request_actual_length`).
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- Yes
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| azure-rtos | usbx | before 6.1.12 | 6.1.12 | Patch available | CNA |
- usbx Vendorazure-rtos Affected before 6.1.12 Fixed in 6.1.12 Patch available CNA
CPE configurations NVD · 1
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:eclipse:threadx_usbx:*:*:*:*:*:*:*:* | before 6.1.12 | Vulnerable | Eclipse Foundation |
- cpe:2.3:a:eclipse:threadx_usbx:*:*:*:*:*:*:*:* Versions before 6.1.12 Vulnerable ·Eclipse Foundation
Remediation
- Fix · CNA usbx (azure-rtos) Fixed in 6.1.12
Timeline
- 2026-10-02 Threatist record created from CVE-2022-39293
References
More Eclipse Foundation Threadx Usbx vulnerabilities
- TI-2022-16486 USBX Host CDC ECM integer underflow with buffer overflow CVSS 3.1CRITICAL 9.8
- TI-2022-11787 Potential buffer overflow in function DFU upload in Azure RTOS USBX CVSS 3.1CRITICAL 9.8
- TI-2022-11766 Buffer overflow on HUB descriptor in Azure RTOS USBX CVSS 3.1CRITICAL 9.8
- TI-2023-26533 Azure RTOS USBX Remote Code Execution Vulnerability CVSS 3.1CRITICAL 9.8
- TI-2023-26537 Azure RTOS USBX Remote Code Execution Vulnerability CVSS 3.1CRITICAL 9.8
- TI-2023-26536 Azure RTOS USBX Remote Code Execution Vulnerability CVSS 3.1CRITICAL 9.8
Sources
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences