CVE-2015-3766 in Mac OS X
Summary
by MITRE
The kernel in Apple iOS before 8.4.1 and OS X before 10.10.5 does not properly restrict the mach_port_space_info interface, which allows attackers to obtain sensitive memory-layout information via a crafted app.
Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.
Analysis
by VulDB Data Team • 02/02/2025
The vulnerability described in CVE-2015-3766 represents a critical information disclosure flaw within the kernel-level Mach port management system of Apple's operating systems. This weakness exists in iOS versions prior to 8.4.1 and OS X versions prior to 10.10.5, where the mach_port_space_info interface lacks proper access controls and validation mechanisms. The flaw specifically targets the kernel's ability to manage and expose memory layout information through the Mach port subsystem, which serves as the foundation for inter-process communication and system resource management in Apple's operating environments.
The technical implementation of this vulnerability stems from insufficient validation of the mach_port_space_info interface parameters and access controls. Attackers can craft malicious applications that exploit this interface to query and retrieve sensitive information about the kernel's memory layout, including virtual address space mappings and memory region boundaries. This information disclosure occurs because the kernel does not properly enforce privilege checks or validate the scope of queries made through the mach_port_space_info interface, allowing unprivileged processes to access kernel memory metadata that should remain protected. The vulnerability falls under the CWE-200 category of Information Exposure and specifically relates to improper restriction of operations within a recognized security boundary, as defined by the CWE taxonomy.
The operational impact of this vulnerability extends beyond simple information disclosure, as the leaked memory layout information provides attackers with crucial data needed for advanced exploitation techniques such as memory address space layout randomization (ASLR) bypass. By obtaining detailed knowledge of kernel memory mappings, attackers can more effectively perform return-oriented programming (ROP) attacks, kernel exploits, or other advanced persistent threats that rely on precise memory addressing. This vulnerability directly enables techniques categorized under the ATT&CK framework's T1059.003 (Command and Scripting Interpreter: PowerShell) and T1068 (Exploitation for Privilege Escalation) tactics, as it provides the foundational information required for more sophisticated attacks. The exposure of memory layout information significantly reduces the effectiveness of modern exploit mitigations and increases the success probability of subsequent attacks.
Mitigation strategies for CVE-2015-3766 require immediate system updates to the patched versions of iOS 8.4.1 and OS X 10.10.5, which implement proper access controls and parameter validation for the mach_port_space_info interface. Organizations should also implement monitoring for suspicious application behavior that attempts to query kernel memory information through Mach ports, as well as maintain comprehensive patch management programs to ensure all systems remain protected against similar vulnerabilities. Additional defensive measures include implementing kernel extension restrictions, monitoring for unauthorized access to kernel interfaces, and maintaining up-to-date threat intelligence regarding similar information disclosure vulnerabilities in operating system kernels. The vulnerability demonstrates the critical importance of proper kernel interface validation and access control enforcement, as highlighted by the ATT&CK framework's emphasis on privilege escalation techniques and the need for robust kernel security boundaries.