Kernel memory corruption via unchecked UAC3 descriptor length
Published Sep 4, 2025 · Updated May 12, 2026
Out-of-bounds access in Linux ALSA USB audio and SIMATIC CN 4100 before V5.0 allows local users to corrupt kernel memory. The validator in sound/usb/validate.c accepts UAC3 power-domain descriptors without checking their variable bLength before accessing descriptor fields. Reachability requires local attachment or control of malicious USB audio firmware; malformed descriptors can compromise kernel confidentiality, integrity, and availability.
Summary
What happened
Out-of-bounds access in Linux ALSA USB audio and SIMATIC CN 4100 before V5.0 allows local users to corrupt kernel memory. The validator in sound/usb/validate.c accepts UAC3 power-domain descriptors without checking their variable bLength before accessing descriptor fields. Reachability requires local attachment or control of malicious USB audio firmware; malformed descriptors can compromise kernel confidentiality, integrity, and availability.
The record
- CVE
- CVE-2025-38729
- Published
- Sep 4, 2025
- Updated
- May 12, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- CWE-787, T1200
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Sep 4, 2025CVE publishedPublication date reported by the CVE source.
- May 12, 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=4.17
- Affected versionversion=9a2fe9b801f585baccf8352d82839dcd54b300cf <07c8d78dbb5e0ff8b23f7fd69cd1d4e2ba22b3dc
- Affected versionversion=9a2fe9b801f585baccf8352d82839dcd54b300cf <1666207ba0a5973735ef010812536adde6174e81
- Affected versionversion=9a2fe9b801f585baccf8352d82839dcd54b300cf <29b415ec09f5b9d1dfa2423b826725a8c8796b9a
- Affected versionversion=9a2fe9b801f585baccf8352d82839dcd54b300cf <40714daf4d0448e1692c78563faf0ed0f9d9b5c7
- Affected versionversion=9a2fe9b801f585baccf8352d82839dcd54b300cf <452ad54f432675982cc0d6eb6c40a6c86ac61dbd
- Affected versionversion=9a2fe9b801f585baccf8352d82839dcd54b300cf <cd08d390d15b204cac1d3174f5f149a20c52e61a
- Affected versionversion=9a2fe9b801f585baccf8352d82839dcd54b300cf <d832ccbc301fbd9e5a1d691bdcf461cdb514595f
- Affected versionversion=9a2fe9b801f585baccf8352d82839dcd54b300cf <ebc9e06b6ea978a20abf9b87d41afc51b2d745ac
- Affected versionversion=9a2fe9b801f585baccf8352d82839dcd54b300cf <f03418bb9d542f44df78eec2eff4ac83c0a8ac0d
What conditions does exploitation require?
What is affected?
Published CVSS scores
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Attacks
What attackers are doing with it
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Public exploit references
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Technologies
Your stack
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Your stack
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