CyberSecBulletin
CVE-2022-36063NVD status: Modified

usbx: Improper Validation of Specified Quantity in Input

Published Updated By the CyberSecBulletin desk

CVE-2022-36063 is a critical-severity improper validation of specified quantity in input vulnerability in usbx from Azure-rtos, with a CVSS 3.1 base score of 9.8 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected usbx versions: < 6.1.12. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 2.17% chance of exploitation within 30 days, higher than 83% of scored CVEs.

Patch this week

Critical severity: a successful attack would have severe impact.

What to do

  1. Update Threadx Usbx to 6.1.11 or a later version.
  2. Read the advisory on github.com for workarounds and exact fixed builds.
  3. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.

Affected products and versions

VendorProductAffected versionsFixed in
Azure-rtosusbx< 6.1.12Not stated
EclipseThreadx Usbxbefore 6.1.116.1.11

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
NoneNo account or login is needed.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
HighAll data handled by the component can be read.
Integrity
HighData or code can be modified at will.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.

Scoring systemScoreSeverityScored by
CVSS 3.17.6HighCNA (github.com)
CVSS 3.19.8CriticalNVD

Official 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.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Improper Validation of Specified Quantity in Input

The 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.

More Improper Validation of Specified Quantity in Input vulnerabilities (CWE-1284)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: poc, automatable: no, technical impact: partial).
  3. Record last changed materially (score, affected products, status or references).

References

Patches and release notes

Technical write-ups (may include proof of concept)

Other vulnerabilities in usbx

All usbx vulnerabilities

Recent Improper Validation of Specified Quantity in Input vulnerabilities

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