CVE-2021-47120

Local system crash via uninitialized driver data

Published Mar 15, 2024 · Updated May 11, 2026

NULL pointer dereference in the Linux kernel allows local users to crash the system by disconnecting a malformed Apple trackpad. The magicmouse probe path returns success when its Apple trackpad sanity check fails, leaving driver data uninitialized for the remove callback. Local access to connect or unbind a nonconforming Magic Trackpad 2-class USB device is required; the resulting null dereference interrupts the host.

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

What happened

NULL pointer dereference in the Linux kernel allows local users to crash the system by disconnecting a malformed Apple trackpad. The magicmouse probe path returns success when its Apple trackpad sanity check fails, leaving driver data uninitialized for the remove callback. Local access to connect or unbind a nonconforming Magic Trackpad 2-class USB device is required; the resulting null dereference interrupts the host.

The record

CVE
CVE-2021-47120
Published
Mar 15, 2024
Updated
May 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-476, T1499.004
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Mar 15, 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

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=4.20
  2. Affected versionversion=9d7b18668956c411a422d04c712994c5fdb23a4b <368c5d45a87e1bcc7f1e98e0c255c37b7b12c5d6
  3. Affected versionversion=9d7b18668956c411a422d04c712994c5fdb23a4b <4b4f6cecca446abcb686c6e6c451d4f1ec1a7497
  4. Affected versionversion=9d7b18668956c411a422d04c712994c5fdb23a4b <9cf27473f21913a3eaf4702dd2a25415afd5f33f
  5. Affected versionversion=9d7b18668956c411a422d04c712994c5fdb23a4b <b5d013c4c76b276890135b5d32803c4c63924b77

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=4.20; version=9d7b18668956c411a422d04c712994c5fdb23a4b <368c5d45a87e1bcc7f1e98e0c255c37b7b12c5d6; version=9d7b18668956c411a422d04c712994c5fdb23a4b <4b4f6cecca446abcb686c6e6c451d4f1ec1a7497; version=9d7b18668956c411a422d04c712994c5fdb23a4b <9cf27473f21913a3eaf4702dd2a25415afd5f33f; version=9d7b18668956c411a422d04c712994c5fdb23a4b <b5d013c4c76b276890135b5d32803c4c63924b77

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.

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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-476NULL Pointer Dereference
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

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Your stack

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