CVE-2022-3431 in Notebook
Summary
by MITRE • 10/25/2023
A potential vulnerability in a driver used during manufacturing process on some consumer Lenovo Notebook devices that was mistakenly not deactivated may allow an attacker with elevated privileges to modify secure boot setting by modifying an NVRAM variable.
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Analysis
by VulDB Data Team • 10/28/2023
The vulnerability identified as CVE-2022-3431 represents a critical security flaw within the manufacturing process of certain Lenovo notebook devices, specifically affecting the secure boot configuration through improper driver activation. This issue stems from a manufacturing driver that was inadvertently left active during production, creating an unauthorized pathway for privilege escalation and system configuration modification. The flaw exists within the firmware layer of these devices, where a driver intended for manufacturing purposes was not properly disabled before the final product deployment, leaving a persistent backdoor in the system architecture.
The technical exploitation of this vulnerability occurs through manipulation of Non-Volatile Random Access Memory (NVRAM) variables, which store critical system configuration parameters including secure boot settings. When the manufacturing driver remains active, it provides elevated access to NVRAM modification capabilities that should normally be restricted to authorized system components. This allows an attacker with already elevated privileges to alter the secure boot configuration, potentially enabling the execution of unsigned code or modification of system firmware components. The vulnerability specifically targets the UEFI firmware environment where secure boot policies are enforced, making it particularly dangerous as it undermines the fundamental security model designed to prevent unauthorized system modifications.
From an operational impact perspective, this vulnerability creates a significant risk for organizations and individuals using affected Lenovo notebook devices, as it enables attackers to bypass the secure boot mechanism that protects against rootkits and boot-level malware. The vulnerability's exposure during manufacturing means that devices shipped to end users may contain persistent access mechanisms that could be exploited to establish persistent backdoors. The attack surface is particularly concerning because it requires only elevated privileges to exploit, which may be obtained through other means such as physical access or social engineering attacks that compromise user accounts. This vulnerability essentially allows attackers to create a persistent state where they can modify system security policies without detection.
The mitigation strategies for CVE-2022-3431 primarily involve firmware updates from Lenovo that properly deactivate the manufacturing driver and ensure all NVRAM variables are protected from unauthorized modification. Organizations should implement comprehensive device inventory management to identify affected systems and apply patches immediately. System administrators should also monitor for unauthorized changes to secure boot configurations and implement additional security controls such as hardware-based root of trust mechanisms and firmware integrity monitoring. This vulnerability aligns with CWE-284 Access Control Issues and maps to attack techniques in the ATT&CK framework under T1014 Rootkit and T1068 Exploitation for Privilege Escalation, highlighting the need for layered security approaches that protect against both external attacks and insider threats that might exploit such manufacturing backdoors.