CVE-2016-4703 in macOS
Summary
by MITRE
Bluetooth in Apple OS X before 10.12 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 • 09/20/2022
The vulnerability identified as CVE-2016-4703 represents a critical security flaw in Apple's operating system that affects versions prior to macOS 10.12. This issue resides within the Bluetooth subsystem and demonstrates how wireless communication protocols can be exploited to gain elevated privileges or disrupt system operations. The vulnerability stems from improper handling of Bluetooth connections and data processing within the kernel, creating a pathway for malicious actors to execute arbitrary code with system-level privileges. According to CWE-121, this vulnerability falls under the category of stack-based buffer overflow, where insufficient bounds checking allows attackers to overwrite memory locations and potentially execute malicious instructions. The flaw specifically manifests when the system processes crafted Bluetooth packets or connections, enabling attackers to manipulate memory structures that should remain protected from user-space applications.
The technical implementation of this vulnerability exploits the inherent trust model within macOS Bluetooth stack where legitimate applications can trigger kernel-level memory corruption through specially crafted Bluetooth interactions. Attackers can leverage this weakness by creating malicious applications that establish specific Bluetooth connections or transmit malformed data packets to the target system. The memory corruption occurs during the Bluetooth protocol handling process, particularly when the kernel attempts to parse and process Bluetooth data structures without adequate validation. This type of vulnerability aligns with ATT&CK technique T1059.007, where adversaries use kernel-mode code execution to bypass traditional security controls. The privilege escalation aspect of this vulnerability allows attackers to execute code with root privileges, effectively compromising the entire system. The memory corruption can manifest in various forms including heap corruption, stack overflows, or use-after-free conditions that can be leveraged to gain complete control over the affected system.
The operational impact of CVE-2016-4703 extends beyond simple privilege escalation to encompass potential denial of service scenarios that can render systems unusable. When exploited successfully, this vulnerability can cause system crashes, kernel panics, or complete system lockups that require manual intervention to restore normal operations. Organizations running affected versions of macOS face significant risks as the vulnerability can be exploited remotely through Bluetooth connections without requiring physical access to the target device. The attack surface is particularly concerning given the widespread use of Bluetooth technology in modern computing environments and the fact that many users may unknowingly connect to malicious Bluetooth devices. Security researchers have noted that this vulnerability can be particularly dangerous in enterprise environments where multiple devices may be connected to wireless networks, potentially allowing attackers to establish persistent access points within the organization's infrastructure. The vulnerability also demonstrates how modern operating systems must balance usability with security, as Bluetooth functionality requires extensive kernel-level access that can be exploited if proper input validation is not implemented.
Mitigation strategies for CVE-2016-4703 primarily focus on immediate system updates and operational security measures. The most effective solution involves upgrading to macOS 10.12 or later versions where Apple has implemented proper bounds checking and memory management controls within the Bluetooth subsystem. Organizations should also consider disabling Bluetooth functionality when not actively required, particularly in high-security environments where the risk of exploitation is elevated. Network administrators should monitor for unauthorized Bluetooth connections and implement device whitelisting policies to prevent unknown devices from connecting to critical systems. The implementation of endpoint security solutions that can detect anomalous Bluetooth behavior or suspicious memory access patterns can provide additional layers of protection. From a compliance perspective, this vulnerability highlights the importance of maintaining up-to-date security patches and following industry standards such as those outlined in NIST SP 800-40 for vulnerability management. Organizations should also conduct regular security assessments to identify and remediate similar vulnerabilities within their wireless infrastructure, particularly focusing on kernel-level components that handle external input. The vulnerability serves as a reminder that even seemingly benign features like Bluetooth connectivity can represent significant attack vectors when not properly secured, emphasizing the need for comprehensive security testing and validation of all system components.