CVE-2016-1735 in Mac OS X
Summary
by MITRE
Bluetooth 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, a different vulnerability than CVE-2016-1736.
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Analysis
by VulDB Data Team • 07/11/2022
The vulnerability identified as CVE-2016-1735 represents a critical security flaw in Apple's operating system that affected versions prior to 10.11.4. This issue specifically targets the Bluetooth subsystem and demonstrates how wireless communication protocols can be exploited to gain elevated privileges within the operating system. The vulnerability falls under the category of privilege escalation and memory corruption, making it particularly dangerous as it could allow attackers to execute arbitrary code with system-level privileges. The flaw is classified as a heap-based buffer overflow or memory corruption issue that occurs during Bluetooth protocol processing, which is a common attack vector in modern operating systems where wireless protocols are extensively utilized. This vulnerability is distinct from CVE-2016-1736, indicating that Apple's Bluetooth implementation contained multiple separate security weaknesses that required individual patches.
The technical exploitation of CVE-2016-1735 occurs when a malicious application crafted to manipulate Bluetooth communication protocols is executed on an affected system. The vulnerability stems from improper input validation within the Bluetooth stack where crafted data packets or malformed Bluetooth communications can cause memory corruption in kernel space. When the operating system processes these malicious inputs, it leads to unpredictable behavior including potential code execution in privileged contexts or system crashes resulting in denial of service. The attack requires local execution capabilities since the malicious application must be able to interact with the Bluetooth subsystem, but once successful, the attacker gains access to system-level privileges that would normally be restricted to legitimate system processes. This represents a classic example of a kernel-level vulnerability where user-space applications can exploit protocol handlers to gain unauthorized access to system resources and execute arbitrary code with root privileges.
The operational impact of this vulnerability extends beyond simple privilege escalation as it creates potential for complete system compromise when combined with other attack vectors. An attacker who successfully exploits this vulnerability could potentially install persistent backdoors, modify system files, access sensitive user data, or establish covert communication channels through the Bluetooth interface. The memory corruption aspect of the vulnerability also makes it particularly challenging to detect since system crashes may appear as random failures rather than obvious signs of exploitation. Organizations running affected versions of macOS were at risk of unauthorized access to their systems, with the potential for data breaches, system hijacking, and network infiltration through the Bluetooth interface. The vulnerability's presence in the core operating system components makes it particularly concerning as it affects the fundamental security architecture of Apple's platform and could be leveraged for advanced persistent threats. This vulnerability aligns with ATT&CK framework techniques related to privilege escalation and defense evasion, as attackers could use it to maintain persistent access while avoiding detection through legitimate system interfaces.
Mitigation strategies for CVE-2016-1735 primarily focus on immediate system updates and operational security measures. The most effective solution is to upgrade to Apple OS X 10.11.4 or later versions where the vulnerability has been patched through proper input validation and memory management improvements. System administrators should implement comprehensive patch management policies to ensure all endpoints are updated promptly, as this vulnerability could be exploited by automated malware or targeted attacks. Network monitoring solutions should be configured to detect unusual Bluetooth activity patterns that might indicate exploitation attempts, though the vulnerability itself requires local execution. Organizations should also consider disabling Bluetooth functionality when not actively needed, particularly in high-security environments, and implement application whitelisting policies to prevent execution of untrusted applications. The patch addresses the underlying memory corruption issue by strengthening input validation in the Bluetooth protocol handlers and implementing proper bounds checking to prevent buffer overflows. This vulnerability demonstrates the importance of maintaining current operating system versions and highlights the risks associated with legacy systems that may not receive security updates, particularly in enterprise environments where system compatibility requirements might delay critical patches.