CVE-2022-36063: azure-rtos usbx Stack-based Buffer Overflow

Vulnerability summary

CVE-2022-36063 is a critical (CVSS 9.8) Stack-based Buffer Overflow vulnerability in azure-rtos usbx. EPSS estimates a 2.14% chance of exploitation in the next 30 days, higher than 81.7% of scored vulnerabilities. 1 public exploit is recorded.

Timeline

1. 10-10-2022
   PublishedVulnerability first disclosed.
2. 22-04-2025
   Last modifiedVulnerability information updated.

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.

• CWE-121Stack-based Buffer OverflowA stack-based buffer overflow condition is a condition where the buffer being overwritten is allocated on the stack (i.e., is a local variable or, rarely, a parameter to a function).
• CWE-191Integer Underflow (Wrap or Wraparound)The product subtracts one value from another, such that the result is less than the minimum allowable integer value, which produces a value that is not equal to the correct result.
• CWE-1284Improper Validation of Specified Quantity in InputThe product receives input that is expected to specify a quantity (such as size or length), but it does not validate or incorrectly validates that the quantity has the required properties.