CVE-2021-47334

Kernel memory corruption via stale input-device cleanup

Published May 21, 2024 · Updated May 11, 2026

Use-after-free in the Linux kernel ibmasm driver allows local users to corrupt kernel memory after device initialization fails. ibmasm_init_one frees mouse and keyboard input devices on one error path, then passes their stale pointers to ibmasm_free_remote_input_dev for unregistration on a second path. Reachability requires the IBM ASM driver and a remote-input initialization failure; resulting memory corruption can compromise or interrupt the host.

CVSS severity7.8
High
EPSS probability0.28%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Use-after-free in the Linux kernel ibmasm driver allows local users to corrupt kernel memory after device initialization fails. ibmasm_init_one frees mouse and keyboard input devices on one error path, then passes their stale pointers to ibmasm_free_remote_input_dev for unregistration on a second path. Reachability requires the IBM ASM driver and a remote-input initialization failure; resulting memory corruption can compromise or interrupt the host.

The record

CVE
CVE-2021-47334
Published
May 21, 2024
Updated
May 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-416, T1068
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. May 21, 2024CVE publishedPublication date reported by the CVE source.
  2. May 11, 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.

  1. Affected versionversion=2.6.16
  2. Affected versionversion=736ce43295682d060f2b93624b4a339f9af6aab1 <1512e7dc5eb08b7d92a12e2bfcd9cb8c4a1ec069
  3. Affected versionversion=736ce43295682d060f2b93624b4a339f9af6aab1 <29ba8e2ba89ee2862a26d91204dd5fe77ceee25a
  4. Affected versionversion=736ce43295682d060f2b93624b4a339f9af6aab1 <38660031e80eaa6cc9370b031c180612f414b00d
  5. Affected versionversion=736ce43295682d060f2b93624b4a339f9af6aab1 <481a76d4749ee3a27f902ba213fdcbb4bb39720e
  6. Affected versionversion=736ce43295682d060f2b93624b4a339f9af6aab1 <5b06ca113bf197aab2ab61288f42506e0049fbab
  7. Affected versionversion=736ce43295682d060f2b93624b4a339f9af6aab1 <7272b591c4cb9327c43443f67b8fbae7657dd9ae
  8. Affected versionversion=736ce43295682d060f2b93624b4a339f9af6aab1 <a7268e8a227d5a4f0bd1584f556246b0224ab274
  9. Affected versionversion=736ce43295682d060f2b93624b4a339f9af6aab1 <b9c87ce3bc6331f82811a8cf8e930423c22523a3
  10. Affected versionversion=736ce43295682d060f2b93624b4a339f9af6aab1 <ef1067d2baa847d53c9988510d99fb494de4d12c

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=2.6.16; version=736ce43295682d060f2b93624b4a339f9af6aab1 <1512e7dc5eb08b7d92a12e2bfcd9cb8c4a1ec069; version=736ce43295682d060f2b93624b4a339f9af6aab1 <29ba8e2ba89ee2862a26d91204dd5fe77ceee25a; version=736ce43295682d060f2b93624b4a339f9af6aab1 <38660031e80eaa6cc9370b031c180612f414b00d; version=736ce43295682d060f2b93624b4a339f9af6aab1 <481a76d4749ee3a27f902ba213fdcbb4bb39720e; version=736ce43295682d060f2b93624b4a339f9af6aab1 <5b06ca113bf197aab2ab61288f42506e0049fbab; version=736ce43295682d060f2b93624b4a339f9af6aab1 <7272b591c4cb9327c43443f67b8fbae7657dd9ae; version=736ce43295682d060f2b93624b4a339f9af6aab1 <a7268e8a227d5a4f0bd1584f556246b0224ab274; version=736ce43295682d060f2b93624b4a339f9af6aab1 <b9c87ce3bc6331f82811a8cf8e930423c22523a3; version=736ce43295682d060f2b93624b4a339f9af6aab1 <ef1067d2baa847d53c9988510d99fb494de4d12c

Published CVSS scores

7.8NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
7.8CanonicalCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/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.

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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

CWE-416Use After Free
T1068Exploitation for Privilege Escalation

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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