CVE-2022-40136 in Lenovo
Summary
by MITRE • 01/31/2023
An information leak vulnerability in SMI Handler used to configure platform settings over WMI in some Lenovo models may allow an attacker with local access and elevated privileges to read SMM memory.
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Analysis
by VulDB Data Team • 01/31/2023
The vulnerability identified as CVE-2022-40136 represents a critical information disclosure flaw within the SMI Handler component of certain Lenovo computer models. This vulnerability specifically affects systems that utilize Windows Management Instrumentation for platform configuration and settings management. The SMI Handler serves as a crucial interface between the operating system and the System Management Mode, which operates with the highest privilege level and direct hardware access. When an attacker gains local access to a vulnerable system and achieves elevated privileges, they can exploit this flaw to read sensitive data from System Management Mode memory regions.
The technical root cause of this vulnerability lies in improper access controls within the SMI Handler implementation. System Management Mode operates outside the normal operating system execution environment and has unrestricted access to system hardware and memory. The flaw occurs when the SMI Handler fails to properly validate memory access requests from privileged local users, allowing unauthorized reading of SMM memory contents. This type of vulnerability falls under the CWE-200 category for "Information Exposure" and represents a significant bypass of the security model that separates normal operating system execution from the more privileged SMM environment. The vulnerability specifically impacts Lenovo systems where WMI is used for platform configuration, making it particularly concerning for enterprise environments where these systems are commonly deployed.
The operational impact of this vulnerability extends beyond simple information disclosure, as SMM memory often contains sensitive system configuration data, cryptographic keys, firmware information, and other critical system components. An attacker who successfully exploits this vulnerability could potentially extract firmware passwords, cryptographic keys used for system authentication, or other confidential data stored in SMM memory regions. This information could then be leveraged to escalate privileges further or conduct more sophisticated attacks against the system. The vulnerability demonstrates a failure in the principle of least privilege, where local users with elevated privileges can access memory areas that should remain protected from such access. According to ATT&CK framework, this vulnerability maps to T1059.007 for "Command and Scripting Interpreter: Windows Command Shell" and T1068 for "Exploitation for Privilege Escalation," representing the attack paths that adversaries might use to exploit this weakness.
Mitigation strategies for CVE-2022-40136 should begin with immediate patch deployment from Lenovo, as the vendor has released firmware updates to address this specific vulnerability. Organizations should prioritize patching all affected Lenovo systems, particularly those in enterprise environments where the risk of exploitation is higher. System administrators should implement monitoring for unusual SMI handler activity or memory access patterns that might indicate exploitation attempts. Additionally, security teams should conduct thorough vulnerability assessments to identify all affected systems within their infrastructure and establish baseline configurations that minimize the attack surface. The vulnerability highlights the importance of proper privilege management and memory isolation in secure system design, emphasizing that even elevated local users should not be granted access to SMM memory regions without proper justification and validation. Regular security assessments and firmware updates are essential to maintain protection against similar vulnerabilities in the rapidly evolving threat landscape.