CVE-2017-3746 in ThinkPad USB 3.0 Ethernet Adapter
Summary
by MITRE
ThinkPad USB 3.0 Ethernet Adapter (part number 4X90E51405) driver, various versions, was found to contain a privilege escalation vulnerability that could allow a local user to execute arbitrary code with administrative or system level privileges.
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Analysis
by VulDB Data Team • 11/11/2019
The ThinkPad USB 3.0 Ethernet Adapter represents a widely deployed network hardware component manufactured by Lenovo, designed to provide high-speed internet connectivity through usb 3.0 interfaces. This particular device utilizes a proprietary driver software stack that facilitates communication between the hardware adapter and the operating system. The vulnerability under examination affects specific versions of this driver software, creating a critical security weakness that undermines the system's privilege model. The affected driver implementation contains a flaw that allows unauthorized code execution within elevated privilege contexts, fundamentally compromising system security boundaries. This issue manifests specifically within the kernel-mode driver component that manages network interface operations and hardware abstraction layers.
The technical flaw resides in improper privilege validation mechanisms within the driver's kernel-space implementation. When the driver processes certain ioctl (input/output control) commands or system calls from user-mode applications, it fails to properly validate the privilege level of the calling process. This validation failure creates a path where unprivileged user processes can manipulate driver interfaces to execute code with elevated privileges. The vulnerability stems from insufficient access control checks that should normally prevent non-privileged processes from triggering privileged operations. According to cwe taxonomy, this represents a cwe-269: privilege escalation vulnerability through improper access control mechanisms. The flaw operates by exploiting a race condition or improper input validation that allows crafted driver requests to bypass normal privilege enforcement checks, effectively creating a backdoor for privilege elevation.
The operational impact of this vulnerability extends beyond simple privilege escalation to encompass complete system compromise. A local attacker with standard user privileges can leverage this flaw to gain administrative or system-level access, enabling them to install malicious software, modify system configurations, access sensitive data, or establish persistent footholds within the target environment. The implications are particularly severe given that the affected hardware is commonly deployed in enterprise environments where users may have legitimate access to systems but should not possess administrative capabilities. This vulnerability undermines the fundamental security model of operating systems by allowing privilege escalation through legitimate hardware interfaces. The attack surface is further expanded because the vulnerability affects multiple versions of the driver software, making it a widespread concern across various system deployments and potentially affecting numerous enterprise networks simultaneously.
Security professionals should implement immediate mitigations including driver version updates from Lenovo's official sources, system hardening measures to restrict driver access, and monitoring for suspicious privilege escalation activities. The vulnerability aligns with attack techniques described in the attack pattern taxonomy under privilege escalation methods, particularly those involving kernel-mode exploitation. Organizations should conduct comprehensive vulnerability assessments to identify affected systems and implement layered defenses including privilege separation, driver signature verification, and regular security updates. The cwe classification of this vulnerability emphasizes the critical importance of proper privilege management in system drivers and highlights the need for robust access control mechanisms in kernel-space components. Additionally, system administrators should consider implementing application whitelisting policies and monitoring for anomalous driver behavior to detect potential exploitation attempts.