CVE-2022-40137 in Lenovo
Summary
by MITRE • 01/31/2023
A buffer overflow in the WMI SMI Handler in some Lenovo models may allow an attacker with local access and elevated privileges to execute arbitrary code.
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Analysis
by VulDB Data Team • 01/31/2023
The vulnerability identified as CVE-2022-40137 represents a critical buffer overflow flaw within the Windows Management Instrumentation (WMI) SMI Handler component found in specific Lenovo laptop models. This issue resides in the System Management Interrupt (SMI) handler mechanism that operates at a privileged level within the system firmware, making it particularly dangerous as it requires only local access with elevated privileges to exploit. The vulnerability stems from improper bounds checking in the WMI SMI Handler implementation, which fails to validate input parameters before processing them, creating an opportunity for attackers to overwrite adjacent memory locations through carefully crafted buffer inputs.
The technical nature of this vulnerability aligns with CWE-121, which describes stack-based buffer overflow conditions where insufficient bounds checking allows attackers to overwrite adjacent memory locations. The flaw operates at the intersection of firmware and operating system components, leveraging the SMI handler's privileged execution context to potentially escalate privileges and execute arbitrary code. Attackers can exploit this by sending malformed WMI requests through the SMI handler interface, which then triggers the buffer overflow condition during processing. The SMI handler operates at a higher privilege level than typical user applications, meaning that even if an attacker only has local user access, the elevated privileges required for exploitation are already present within the system's management interface.
The operational impact of this vulnerability extends beyond simple code execution capabilities as it provides a potential pathway for persistent system compromise and privilege escalation attacks. The SMI handler's role in system management makes it an attractive target for attackers seeking to establish backdoors or maintain long-term access to affected systems. This vulnerability particularly affects Lenovo models that implement specific firmware configurations, creating a targeted attack surface that requires detailed knowledge of the affected hardware and firmware versions. The exploitation process typically involves crafting malicious WMI requests that trigger the buffer overflow condition, potentially allowing attackers to bypass standard operating system security mechanisms and execute code with system-level privileges.
Mitigation strategies for CVE-2022-40137 should prioritize firmware updates from Lenovo as the primary remediation approach, as the vulnerability exists within the system firmware rather than the operating system itself. Organizations should implement comprehensive inventory management to identify affected Lenovo models and prioritize patching efforts accordingly. The ATT&CK framework categorizes this type of vulnerability under T1068, which describes 'Exploitation for Privilege Escalation', highlighting the potential for attackers to leverage such flaws to gain elevated system access. Additional defensive measures include monitoring for anomalous WMI activity and implementing least privilege principles to limit the potential impact of successful exploitation. System administrators should also consider disabling unnecessary WMI services when possible and employ network segmentation to limit local access to potentially vulnerable systems. The vulnerability demonstrates the importance of firmware security in modern computing environments where hardware-level components can provide attack vectors that bypass traditional software-based security controls.