CVE-2022-4574 in ThinkPad BIOS
Summary
by MITRE • 10/30/2023
An SMI handler input validation vulnerability in the BIOS of some ThinkPad models could allow an attacker with local access and elevated privileges to execute arbitrary code.
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Analysis
by VulDB Data Team • 11/22/2023
The vulnerability identified as CVE-2022-4574 represents a critical security flaw within the System Management Interrupt (SMI) handler of certain ThinkPad laptop models' BIOS implementations. This issue stems from insufficient input validation mechanisms within the SMI handler, which is a critical component responsible for managing system-level operations and maintaining the integrity of the firmware environment. The SMI handler operates in a privileged execution context that provides direct access to hardware resources and system memory, making it a prime target for exploitation by malicious actors who can leverage these privileges to gain deeper system control.
The technical flaw manifests when the SMI handler fails to properly validate input parameters received from system management interfaces, creating potential pathways for attackers to inject malicious code or manipulate system behavior. This vulnerability specifically affects systems where the SMI handler processes external inputs without adequate sanitization or verification checks, allowing crafted payloads to be executed within the SMM (System Management Mode) context. The nature of SMM execution means that any code executed here operates with the highest privilege level, bypassing standard operating system security mechanisms and potentially enabling persistent backdoor access to the affected systems.
From an operational impact perspective, this vulnerability creates significant risk for organizations utilizing affected ThinkPad models, as it requires only local access with elevated privileges to exploit. The attack vector implies that an attacker who has already compromised a system or gained administrative access could leverage this weakness to escalate privileges further, potentially achieving complete system compromise. The implications extend beyond simple code execution, as SMM-based attacks can persist across operating system reboots and are particularly difficult to detect or remediate due to their low-level nature and the complexity of SMM environments. This vulnerability directly impacts the integrity and confidentiality of systems, potentially enabling data exfiltration, persistent surveillance, or complete system takeover operations.
Organizations should implement immediate mitigations including firmware updates from Lenovo to address the identified SMI handler validation issues, ensuring that all affected ThinkPad models receive the necessary BIOS patches. The vulnerability aligns with CWE-20, which addresses improper input validation, and represents a classic example of how firmware-level security flaws can create persistent attack vectors. From an ATT&CK framework perspective, this vulnerability maps to techniques involving privilege escalation and persistence mechanisms, specifically targeting system firmware and low-level system management components. Additionally, organizations should consider implementing runtime protection measures such as SMM protection mechanisms and monitoring for anomalous SMI activity, while also conducting thorough inventory assessments to identify all potentially affected devices within their infrastructure.