CVE-2023-40540

Privileged local information disclosure

Published Nov 14, 2023 · Updated Aug 30, 2024

Information disclosure in some Intel NUC BIOS firmware allows local users with high privileges to read protected data through a side channel. The firmware non-transparently shares microarchitectural resources across security domains, but Intel has not identified the resource or code locus. Exploitation requires high local privileges and high-complexity conditions; the published impact is limited to confidentiality.

CVSS severity4.1
Medium
EPSS probability0.21%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Information disclosure in some Intel NUC BIOS firmware allows local users with high privileges to read protected data through a side channel. The firmware non-transparently shares microarchitectural resources across security domains, but Intel has not identified the resource or code locus. Exploitation requires high local privileges and high-complexity conditions; the published impact is limited to confidentiality.

The record

CVE
CVE-2023-40540
Published
Nov 14, 2023
Updated
Aug 30, 2024
Vendor
Topcon Positioning Systems, Inc.
Product
Intel NUC BIOS Firmware
Classifications
CWE-1303
Attack vector
local
Privileges
admin

Timeline

How it unfolded

  1. Nov 14, 2023CVE publishedPublication date reported by the CVE source.
  2. Aug 30, 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=some Intel(R) NUC BIOS firmware

What conditions does exploitation require?

Attack vectorlocal
Required privilegesadmin

What is affected?

Topcon Positioning Systems, Inc. · Intel NUC BIOS Firmwareversion=some Intel(R) NUC BIOS firmware

Published CVSS scores

4.1Intel CorporationCVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:H/I:N/A:N
4.4NIST NVDCVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:N/A:N

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
Privilegesadmin
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-1303Non-Transparent Sharing of Microarchitectural Resources

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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