Privilege escalation
Published Nov 10, 2021 · Updated Aug 19, 2026
Privilege escalation in Microsoft Azure RTOS USBX before 6.1.9 allows attackers to gain elevated access through a malicious USB device. Microsoft has not published the flawed USBX routine or the operation it performs incorrectly on device-controlled input. Exploitation requires a user to connect the device, and exposure is limited to builds using host audio, video, CDC-ECM, PIMA, or device storage classes.
Summary
What happened
Privilege escalation in Microsoft Azure RTOS USBX before 6.1.9 allows attackers to gain elevated access through a malicious USB device. Microsoft has not published the flawed USBX routine or the operation it performs incorrectly on device-controlled input. Exploitation requires a user to connect the device, and exposure is limited to builds using host audio, video, CDC-ECM, PIMA, or device storage classes.
The record
- CVE
- CVE-2021-42302
- Published
- Nov 10, 2021
- Updated
- Aug 19, 2026
- Vendor
- Microsoft
- Product
- Azure RTOS
- Classifications
- CWE-269
- Attack vector
- local
- Privileges
- unauthenticated
Timeline
How it unfolded
- Nov 10, 2021CVE publishedPublication date reported by the CVE source.
- Aug 19, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=6.0.0 <6.1.9
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
No public exploit references are available in this record.
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
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Your stack
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