CVE-2016-1749 in Mac OS X
Summary
by MITRE
IOUSBFamily in Apple OS X before 10.11.4 allows attackers to execute arbitrary code in a privileged context or cause a denial of service (memory corruption) via a crafted app.
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Analysis
by VulDB Data Team • 01/25/2025
The vulnerability identified as CVE-2016-1749 resides within the IOUSBFamily component of Apple's macOS operating system, affecting versions prior to 10.11.4. This flaw represents a critical security issue that enables attackers to escalate privileges or disrupt system operations through malicious applications. The IOUSBFamily serves as the kernel extension responsible for managing USB device communications and interactions within the operating system, making it a prime target for exploitation due to its privileged execution context and deep integration with the core system architecture.
The technical nature of this vulnerability stems from improper input validation within the USB device handling mechanisms, specifically related to how the system processes crafted USB device descriptors or control requests. When a malicious application attempts to communicate with a USB device through the IOUSBFamily, the kernel fails to properly validate the incoming data structures, leading to memory corruption conditions that can be exploited to execute arbitrary code with kernel-level privileges. This memory corruption typically manifests as buffer overflows or use-after-free conditions that allow attackers to overwrite critical memory locations and manipulate the execution flow of the kernel itself. The vulnerability operates at the kernel level, bypassing standard user-space protections and security boundaries that normally isolate applications from privileged system operations.
The operational impact of CVE-2016-1749 extends beyond simple privilege escalation to include potential system stability threats and comprehensive security compromise. Attackers can leverage this vulnerability to gain root access to affected systems, enabling them to install persistent backdoors, modify system files, steal sensitive data, or establish covert communication channels. The memory corruption aspect also creates opportunities for denial of service attacks that can crash the entire operating system or render specific USB functionality inoperable, affecting legitimate device usage and system reliability. This vulnerability particularly affects enterprise environments where USB devices are frequently used for data transfer, device management, and peripheral connectivity, making it a significant concern for organizations with robust security requirements.
Mitigation strategies for CVE-2016-1749 primarily focus on immediate system updates and operational security measures. Apple addressed this vulnerability through the release of macOS 10.11.4, which included patches to the IOUSBFamily component that properly validate USB device communication protocols and prevent memory corruption conditions. Organizations should prioritize deployment of this update across all affected systems, particularly those handling sensitive data or operating in high-security environments. Additional protective measures include implementing USB device whitelisting policies, disabling unnecessary USB ports, monitoring USB device connections for suspicious activity, and maintaining comprehensive system monitoring to detect potential exploitation attempts. From a cybersecurity framework perspective, this vulnerability aligns with CWE-125, which addresses out-of-bounds read conditions, and maps to ATT&CK technique T1059.003 for execution through kernel modules. The vulnerability also demonstrates the importance of supply chain security and the critical need for thorough testing of kernel-level components, as it represents a fundamental flaw in the operating system's USB subsystem that could be exploited by sophisticated threat actors with minimal technical expertise.