CVE-2021-47434

Controller failure via command-ring pointer corruption

Published May 22, 2024 · Updated May 23, 2026

A race in the Linux xHCI driver allows local users to cause controller memory-access failures through command-ring pointer corruption. The abort path reads CRCR with zeroed pointer bits, then splits a 64-bit write so the controller can stop before an all-zero upper dword overwrites its internal ring pointer. Reaching the flaw requires low-privileged local access, an xHCI controller, and command-abort timing; the bounded consequence is controller memory-access failure.

CVSS severity5.5
Medium
EPSS probability0.24%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

A race in the Linux xHCI driver allows local users to cause controller memory-access failures through command-ring pointer corruption. The abort path reads CRCR with zeroed pointer bits, then splits a 64-bit write so the controller can stop before an all-zero upper dword overwrites its internal ring pointer. Reaching the flaw requires low-privileged local access, an xHCI controller, and command-abort timing; the bounded consequence is controller memory-access failure.

The record

CVE
CVE-2021-47434
Published
May 22, 2024
Updated
May 23, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499.004
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. May 22, 2024CVE publishedPublication date reported by the CVE source.
  2. May 23, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=2818247b6565b7adfbcd53b74509448a8e1fad84
  2. Affected versionversion=3.0.49 <3.1
  3. Affected versionversion=3.2.32 <3.3
  4. Affected versionversion=3.4.13 <3.5
  5. Affected versionversion=3.5.6 <3.6
  6. Affected versionversion=3.6.1 <3.7
  7. Affected versionversion=3.7
  8. Affected versionversion=88bd928daafb5912c269af628b1e5347620c9a62
  9. Affected versionversion=b92cc66c047ff7cf587b318fe377061a353c120f <01c2dcb67e71c351006dd17cbba86c26b7f61eaf
  10. Affected versionversion=b92cc66c047ff7cf587b318fe377061a353c120f <22bcb65ea41072ab5d03c0c6290e04e0df6d09a0
  11. Affected versionversion=b92cc66c047ff7cf587b318fe377061a353c120f <62c182b5e763e5f4062e72678e72ce3e02dd4d1b
  12. Affected versionversion=b92cc66c047ff7cf587b318fe377061a353c120f <dec944bb7079b37968cf69c8a438f91f15c4cc61
  13. Affected versionversion=b92cc66c047ff7cf587b318fe377061a353c120f <e54abefe703ab7c4e5983e889babd1447738ca42
  14. Affected versionversion=b92cc66c047ff7cf587b318fe377061a353c120f <ff0e50d3564f33b7f4b35cadeabd951d66cfc570
  15. Affected versionversion=bc47204b268516ae4085ebdc81a34ddda71b77c4
  16. Affected versionversion=ef6273930e170a4f70a2c7f57a214813c5cf30bb
  17. Affected versionversion=f83994f3e2438b982fb9821d948199b3327638d8

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=2818247b6565b7adfbcd53b74509448a8e1fad84; version=3.0.49 <3.1; version=3.2.32 <3.3; version=3.4.13 <3.5; version=3.5.6 <3.6; version=3.6.1 <3.7; version=3.7; version=88bd928daafb5912c269af628b1e5347620c9a62; version=b92cc66c047ff7cf587b318fe377061a353c120f <01c2dcb67e71c351006dd17cbba86c26b7f61eaf; version=b92cc66c047ff7cf587b318fe377061a353c120f <22bcb65ea41072ab5d03c0c6290e04e0df6d09a0; version=b92cc66c047ff7cf587b318fe377061a353c120f <62c182b5e763e5f4062e72678e72ce3e02dd4d1b; version=b92cc66c047ff7cf587b318fe377061a353c120f <dec944bb7079b37968cf69c8a438f91f15c4cc61; version=b92cc66c047ff7cf587b318fe377061a353c120f <e54abefe703ab7c4e5983e889babd1447738ca42; version=b92cc66c047ff7cf587b318fe377061a353c120f <ff0e50d3564f33b7f4b35cadeabd951d66cfc570; version=bc47204b268516ae4085ebdc81a34ddda71b77c4; version=ef6273930e170a4f70a2c7f57a214813c5cf30bb; version=f83994f3e2438b982fb9821d948199b3327638d8

Published CVSS scores

5.5NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1499.004Application or System Exploitation

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

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo