usbx: Expired Pointer Dereference
CVE-2023-48694 is a critical-severity expired pointer dereference 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: < 6.3.0. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 1.33% chance of exploitation within 30 days, higher than 72% of scored CVEs.
Critical severity: a successful attack would have severe impact.
What to do
- Update Threadx Usbx to 6.3.0 or a later version.
- Read the advisory on github.com for workarounds and exact fixed builds.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Azure-rtos | usbx | < 6.3.0 | Not stated |
| Eclipse | Threadx Usbx | before 6.3.0 | 6.3.0 |
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 system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 6.8 | Medium | CNA (github.com) |
| CVSS 3.1 | 9.8 | Critical | NVD |
Official description
Azure RTOS USBX is a USB host, device, and on-the-go (OTG) embedded stack, that is fully integrated with Azure RTOS ThreadX. An attacker can cause remote code execution due to expired pointer dereference and type confusion vulnerabilities in Azure RTOS USBX. The affected components include functions/processes in host stack and host class, related to device linked classes, ASIX, Prolific, SWAR, audio, CDC ECM in RTOS v6.2.1 and below. The fixes have been included in USBX release 6.3.0. Users are advised to upgrade. There are no known workarounds for this vulnerability.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Expired Pointer Dereference
The product dereferences a pointer that contains a location for memory that was previously valid, but is no longer valid.
How developers prevent this class of flaw
- Choose a language that provides automatic memory management.
- When freeing pointers, be sure to set them to NULL once they are freed. However, the utilization of multiple or complex data structures may lower the usefulness of this strategy.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Advisories
- github.com/azure-rtos/usbx/security/advisories/GHSA-qjw8-7w86-44qjThird Party Advisory
Other vulnerabilities in usbx
- 9.8 Critical severity
- 9.8 Critical severity
- 9.8 Critical severity
- 9.8 Critical severity
- 9.8 Critical severity
- 9.8 Critical severity
Recent Expired Pointer Dereference vulnerabilities
- 7.5 High severity
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