CVE-2021-47101

Data disclosure and service interruption via short reads

Published Mar 4, 2024 · Updated May 11, 2026

Use of uninitialized memory in the Linux ASIX driver allows local users to disclose data or interrupt service through affected kernels. In asix_mdio_read(), asix_read_cmd() can return fewer bytes than the smsr object requires, after which asix_check_host_enable() consumes the uninitialized remainder. The path requires local access and an active ASIX USB network adapter; consequences are limited to kernel-memory disclosure and host interruption.

CVSS severity7.1
High
EPSS probability0.22%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Use of uninitialized memory in the Linux ASIX driver allows local users to disclose data or interrupt service through affected kernels. In asix_mdio_read(), asix_read_cmd() can return fewer bytes than the smsr object requires, after which asix_check_host_enable() consumes the uninitialized remainder. The path requires local access and an active ASIX USB network adapter; consequences are limited to kernel-memory disclosure and host interruption.

The record

CVE
CVE-2021-47101
Published
Mar 4, 2024
Updated
May 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-908
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Mar 4, 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=4.9
  2. Affected versionversion=d9fe64e511144c1ee7d7555b4111f09dde9692ef <8035b1a2a37a29d8c717ef84fca8fe7278bc9f03
  3. Affected versionversion=d9fe64e511144c1ee7d7555b4111f09dde9692ef <d259f621c85949f30cc578cac813b82bb5169f56

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=4.9; version=d9fe64e511144c1ee7d7555b4111f09dde9692ef <8035b1a2a37a29d8c717ef84fca8fe7278bc9f03; version=d9fe64e511144c1ee7d7555b4111f09dde9692ef <d259f621c85949f30cc578cac813b82bb5169f56

Published CVSS scores

7.1NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/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-908Use of Uninitialized Resource

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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