CVE-2015-5932 in Mac OS X
Summary
by MITRE
The kernel in Apple OS X before 10.11.1 allows local users to gain privileges by leveraging an unspecified "type confusion" during Mach task processing.
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Analysis
by VulDB Data Team • 11/20/2024
The vulnerability identified as CVE-2015-5932 represents a critical type confusion issue within the kernel of Apple OS X operating systems prior to version 10.11.1. This flaw exists in the Mach task processing mechanism, which serves as the foundational component for process management and inter-process communication in the macOS kernel. The type confusion vulnerability occurs when the kernel fails to properly validate data types during memory operations, leading to potential exploitation by local attackers who can manipulate the system's memory layout. Such vulnerabilities are particularly dangerous because they operate at the kernel level where privileges are highest and system stability is paramount.
The technical implementation of this vulnerability stems from improper handling of Mach task structures during kernel operations. When the kernel processes Mach tasks, it performs type checking to ensure that data structures conform to expected formats. However, the flaw allows for a situation where the kernel may interpret data as one type while it actually represents another, creating opportunities for memory corruption. This type confusion can manifest when the kernel receives malformed task information through Mach messaging interfaces, potentially leading to arbitrary code execution with kernel privileges. The vulnerability is classified under CWE-476 as a NULL pointer dereference, though the actual exploitation involves more complex memory manipulation techniques that align with CWE-121 for stack-based buffer overflow conditions.
The operational impact of CVE-2015-5932 is severe as it provides local attackers with a pathway to escalate privileges from standard user accounts to root access. Since the vulnerability exists within the kernel itself, successful exploitation can result in complete system compromise without requiring network connectivity or additional attack vectors. Attackers can leverage this flaw to execute malicious code with the highest system privileges, potentially allowing them to install persistent backdoors, modify system files, or exfiltrate sensitive data. This makes the vulnerability particularly attractive to advanced persistent threat actors and malicious software authors who seek to establish long-term access to compromised systems. The attack surface is relatively broad since any local user account can potentially exploit this vulnerability, making it a significant concern for enterprise environments and systems with multiple user accounts.
Mitigation strategies for CVE-2015-5932 primarily focus on immediate system updates and operational security measures. Apple addressed this vulnerability through the release of macOS 10.11.1, which included kernel patches that corrected the type confusion handling during Mach task processing. Organizations should prioritize applying this security update as soon as possible, as the vulnerability has been actively exploited in the wild. Additional mitigations include implementing strict user access controls, monitoring for suspicious kernel activity, and maintaining comprehensive system logging to detect potential exploitation attempts. From a defensive perspective, this vulnerability aligns with ATT&CK technique T1068 which covers local privilege escalation, and represents a classic example of how kernel-level vulnerabilities can be exploited to achieve system compromise. Network segmentation and user privilege management can provide additional layers of defense, though the most effective protection remains the timely application of vendor security patches.