CVE-2021-3718

Physical system crash with Enhanced Biometrics enabled

Published Nov 12, 2021 · Updated Aug 3, 2024

Denial of service in Lenovo ThinkPad BIOS allows physically proximate attackers to crash affected systems with Enhanced Biometrics enabled. Lenovo identifies improper handling of undefined values but has not published the affected firmware locus or the operation that mishandles the value. Exploitation requires physical access and user interaction on a listed ThinkPad with the BIOS setting enabled, and the reported consequence is a system crash.

CVSS severity4.3
Medium
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

Denial of service in Lenovo ThinkPad BIOS allows physically proximate attackers to crash affected systems with Enhanced Biometrics enabled. Lenovo identifies improper handling of undefined values but has not published the affected firmware locus or the operation that mishandles the value. Exploitation requires physical access and user interaction on a listed ThinkPad with the BIOS setting enabled, and the reported consequence is a system crash.

The record

CVE
CVE-2021-3718
Published
Nov 12, 2021
Updated
Aug 3, 2024
Vendor
Lenovo
Product
ThinkPad BIOS
Classifications
CWE-232, T1499
Attack vector
physical
Privileges
unauthenticated

Timeline

How it unfolded

  1. Nov 12, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 2024Record 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=various

What conditions does exploitation require?

Attack vectorphysical
Required privilegesunauthenticated

What is affected?

Lenovo · ThinkPad BIOSversion=various

Published CVSS scores

4.7NIST NVDAV:L/AC:M/Au:N/C:N/I:N/A:C
4.3Lenovo Group Ltd.CVSS:3.1/AV:P/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
4.6NIST NVDCVSS:3.1/AV:P/AC:L/PR:N/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)
Vectorphysical
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-232Improper Handling of Undefined Values
T1499Endpoint Denial of Service

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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