Kernel-address disclosure via unchecked GPIO line offsets
Published Nov 10, 2021 · Updated Aug 19, 2026
Information disclosure in Microsoft Azure Sphere before 22.07 allows local users to infer kernel-memory addresses via a crafted GPIO ioctl. The GPIO_SET_PIN_CONFIG_IOCTL path fails to validate each lineoffsets index before dereferencing gdev->descs, turning return codes into a 32-bit equality oracle. A device-resident application with manifest-granted GPIO access can locate kernel structures, including its credential structure; no direct memory read is exposed.
Summary
What happened
Information disclosure in Microsoft Azure Sphere before 22.07 allows local users to infer kernel-memory addresses via a crafted GPIO ioctl. The GPIO_SET_PIN_CONFIG_IOCTL path fails to validate each lineoffsets index before dereferencing gdev->descs, turning return codes into a 32-bit equality oracle. A device-resident application with manifest-granted GPIO access can locate kernel structures, including its credential structure; no direct memory read is exposed.
The record
- CVE
- CVE-2021-41374
- Published
- Nov 10, 2021
- Updated
- Aug 19, 2026
- Vendor
- Microsoft
- Product
- Azure Sphere
- Classifications
- CWE-129, CAPEC-100
- 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=20.00 <22.07
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.
Public exploit references
- GPIO line-offset kernel-address oracle proof of conceptproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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