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Fencer Intel
high 7.6

CVE-2022-36063 json

USBX Host CDC ECM integer underflow with buffer overflow

published 4y ago modified 4mo ago also EUVD-2022-38825

cvss
7.6
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
2.2%
EPSS 2.2% chance of exploitation in 30 days, percentile 82%
public exploits
0
none known

Summary

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.

Patch / fix

  • eclipse threadx_usbx 6.1.11

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CISA SSVC

Exploitation
Proof of concept is public
Automatable
no
Technical impact
partial
Assessed
last yr.

Exploit prediction

2.19% chance of exploitation in the next 30 days, higher than 82% of all scored CVEs (FIRST EPSS, 2026-11-09).

Exploits and checks

  • github.com https://github.com/azure-rtos/usbx/security/advisories/GHSA-chpp-5fv9-6368 referenced PoC, tagged "exploit" by a source, unverified
  • github.com https://github.com/azure-rtos/usbx/blob/master/common/usbx_host_classes/src/ux_host_class_cdc_ecm_mac_address_get.c#L264 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 7.6 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:H
NVD 3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected products

  • azure-rtos usbx

Classification

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

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.