Potential BIOS Vulnerability in Lenovo Notebook Devices
CVE-2021-3972

6.7MEDIUM

Key Information:

Vendor
Lenovo
Status
Notebook BiOS
Vendor
CVE Published:
22 April 2022

Badges

👾 Exploit Exists🟡 Public PoC

Summary

A potential vulnerability exists in the BIOS of certain Lenovo Notebook devices, where a driver used during the manufacturing process was inadvertently left active. This flaw permits an attacker with elevated privileges to alter the secure boot settings by manipulating an NVRAM variable. Such modifications could compromise the integrity of the device’s boot process, leading to unauthorized access and potential exploitation.

Affected Version(s)

Notebook BIOS various

Exploit Proof of Concept (PoC)

PoC code is written by security researchers to demonstrate the vulnerability can be exploited. PoC code is also a key component for weaponization which could lead to ransomware.

CVE-2021-3972
Created by killvxk

References

https://support.lenovo.com/us/en/product_security/LEN-73440
x_refsource_MISC

CVSS V3.1

Score:
6.7
Severity:
MEDIUM
Confidentiality:
High
Integrity:
High
Availability:
High
Attack Vector:
Local
Attack Complexity:
Low
Privileges Required:
High
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • 🟡

    Public PoC available

  • 👾

    Exploit known to exist

  • Vulnerability Reserved

Credit

Lenovo thanks Martin Smolár from ESET for reporting this issue.
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