CVE-2023-43576 in Desktop BIOS
Summary
by MITRE • 11/09/2023
A buffer overflow was reported in the WMISwSmi module in some Lenovo Desktop products that may allow a local attacker with elevated privileges to execute arbitrary code.
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Analysis
by VulDB Data Team • 11/09/2023
The vulnerability identified as CVE-2023-43576 represents a critical buffer overflow condition within the WMISwSmi module of specific Lenovo desktop computer models. This flaw exists in the Windows Management Instrumentation (WMI) subsystem that handles system management and monitoring functions. The vulnerability specifically affects systems where the WMISwSmi module is active and running with elevated privileges, creating a potential attack vector for local adversaries who have already gained administrative access to the system. The buffer overflow occurs during the processing of certain WMI requests that are handled by this particular module, which is responsible for managing system information and providing interfaces for system management tasks.
The technical nature of this vulnerability stems from improper input validation within the WMISwSmi module where insufficient bounds checking allows an attacker to write data beyond the allocated buffer space. This condition typically arises when the module receives a WMI request containing maliciously crafted parameters that exceed the expected buffer size. The flaw is classified under CWE-121 as a stack-based buffer overflow, which occurs when a program writes beyond the boundaries of a fixed-length buffer allocated on the stack. The attack requires a local attacker who already possesses elevated privileges, as the vulnerability does not allow for privilege escalation but rather provides a means to execute arbitrary code within the elevated context. The module operates with high privileges due to its role in system management, making it an attractive target for attackers seeking to maintain persistence or escalate their capabilities within the compromised system.
The operational impact of this vulnerability extends beyond simple code execution, as it provides attackers with a mechanism to potentially bypass security controls and maintain persistent access to affected systems. Since the module runs with elevated privileges, any code execution achieved through this buffer overflow would operate at the highest privilege level available to the WMI subsystem. This could enable attackers to modify system configurations, install malware, access sensitive data, or establish backdoors that persist across system reboots. The vulnerability affects Lenovo desktop products that implement the WMISwSmi module, which typically includes business and enterprise models that rely heavily on WMI for system monitoring and management. The attack surface is particularly concerning in enterprise environments where WMI is frequently used for remote management and automated system tasks, as these systems may be more vulnerable to exploitation if attackers can leverage this condition.
Mitigation strategies for CVE-2023-43576 primarily focus on patch management and system hardening measures. Lenovo has released firmware updates and system updates that address this vulnerability by implementing proper bounds checking and input validation within the WMISwSmi module. Organizations should prioritize applying these updates immediately to all affected Lenovo desktop systems, particularly those in enterprise environments where the risk of exploitation is higher. System administrators should also consider implementing additional monitoring for unusual WMI activity and suspicious process execution patterns that might indicate exploitation attempts. The vulnerability aligns with ATT&CK technique T1059.001 for command and scripting interpreter and T1068 for exploit for privilege escalation, as it provides a means for code execution within elevated contexts. Network segmentation and privilege separation measures can help reduce the impact if the vulnerability is exploited, though the local nature of the attack means that traditional network-based defenses may be less effective. Security teams should also conduct thorough vulnerability assessments to identify all affected systems and implement monitoring solutions that can detect anomalous behavior in WMI-related processes, as the attack typically occurs through legitimate system management interfaces that may not trigger traditional security alerts.