CVE-2023-25494

Privileged NVRAM variable writes via undisclosed BIOS flaw

Published Apr 5, 2024 · Updated Aug 2, 2024

Out-of-bounds read in Lenovo Desktop, Smart Edge, and ThinkStation BIOS allows local users with elevated privileges to write NVRAM variables. Lenovo identifies the affected locus only as BIOS and has not disclosed the out-of-bounds operation, its input, or how it enables variable writes. The access gate is local elevated privileges, and the reported consequence is modification of firmware configuration stored in NVRAM.

CVSS severity6.7
Medium
EPSS probability0.18%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Out-of-bounds read in Lenovo Desktop, Smart Edge, and ThinkStation BIOS allows local users with elevated privileges to write NVRAM variables. Lenovo identifies the affected locus only as BIOS and has not disclosed the out-of-bounds operation, its input, or how it enables variable writes. The access gate is local elevated privileges, and the reported consequence is modification of firmware configuration stored in NVRAM.

The record

CVE
CVE-2023-25494
Published
Apr 5, 2024
Updated
Aug 2, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-125, T1542.001
Attack vector
local
Privileges
admin

Timeline

How it unfolded

  1. Apr 5, 2024CVE publishedPublication date reported by the CVE source.
  2. Aug 2, 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?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectorlocal
Required privilegesadmin

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

6.7LenovoCVSS:3.1/AV:L/AC:L/PR:H/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
Privilegesadmin
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-125Out-of-bounds Read
T1542.001Pre-OS Boot System Firmware

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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