CVE-2015-7110 in Mac OS X
Summary
by MITRE
The Disk Images component in Apple OS X before 10.11.2 and tvOS before 9.1 allows local users to gain privileges or cause a denial of service (memory corruption) via a crafted disk image.
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Analysis
by VulDB Data Team • 06/22/2024
The vulnerability identified as CVE-2015-7110 resides within Apple's Disk Images component, a critical system element responsible for handling various disk image formats including dmg, iso, and others. This component operates with elevated privileges and serves as the foundation for mounting and interacting with disk images across Apple's operating systems. The flaw manifests in the component's insufficient validation of disk image metadata and structure, creating opportunities for maliciously crafted disk images to exploit memory handling mechanisms within the system's kernel. The vulnerability affects Apple OS X versions prior to 10.11.2 and tvOS versions prior to 9.1, representing a significant security gap that could be leveraged by local attackers to execute arbitrary code with system-level privileges.
The technical implementation of this vulnerability stems from improper bounds checking and memory management within the disk image parsing routines. When the system processes a crafted disk image, the parsing logic fails to properly validate the size and structure of various image components, leading to potential buffer overflows or use-after-free conditions in memory. This memory corruption occurs during the image mounting process when the system attempts to parse metadata fields that have been deliberately manipulated to exceed expected boundaries. The vulnerability is classified under CWE-125 as an out-of-bounds read and CWE-787 as an out-of-bounds write, representing fundamental flaws in memory safety that enable privilege escalation attacks.
From an operational perspective, this vulnerability presents a severe threat to system integrity and security posture. Local attackers can exploit this weakness by creating specially crafted disk images that, when mounted by an unsuspecting user, trigger the memory corruption in the kernel space. The successful exploitation results in either privilege escalation to root level access or denial of service conditions that can crash the system. This vulnerability directly maps to ATT&CK technique T1068 which involves exploiting legitimate credentials or privileges to gain higher-level access. The impact extends beyond individual system compromise as it can serve as a foothold for broader network infiltration or as part of multi-stage attack chains targeting Apple environments.
The mitigation strategies for CVE-2015-7110 primarily focus on immediate system updates and security hardening measures. Apple released patches for OS X 10.11.2 and tvOS 9.1 that address the memory handling issues in the Disk Images component through improved input validation and bounds checking. Organizations should prioritize patch deployment across all affected systems and implement monitoring for suspicious disk image mounting activities. Additional protective measures include disabling automatic disk image mounting for untrusted sources, implementing disk image verification procedures, and establishing network segmentation to limit the potential impact of successful exploitation attempts. Security teams should also consider implementing behavioral monitoring to detect anomalous disk image processing activities that might indicate exploitation attempts. The vulnerability underscores the importance of maintaining up-to-date system patches and demonstrates how seemingly benign system components can serve as critical attack vectors when subjected to improper input validation.