CVE-2015-7067 in Mac OS X
Summary
by MITRE
IOThunderboltFamily in Apple OS X before 10.11.2 allows local users to cause a denial of service (NULL pointer dereference) via an unspecified userclient type.
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Analysis
by VulDB Data Team • 11/12/2024
The CVE-2015-7067 vulnerability resides within the IOThunderboltFamily component of Apple's macOS operating system, specifically affecting versions prior to 10.11.2. This flaw represents a critical security issue that demonstrates the dangers of improper input validation in kernel-level drivers. The vulnerability manifests as a NULL pointer dereference when handling userclient types, creating a potential denial of service condition that can be exploited by local attackers with minimal privileges. The IOThunderboltFamily is responsible for managing Thunderbolt hardware connections and interfaces, making it a crucial component in macOS system architecture.
The technical exploitation of this vulnerability occurs when an attacker crafts malicious input through the Thunderbolt userclient interface, triggering a scenario where the kernel attempts to dereference a NULL pointer during processing of the userclient type. This type of flaw falls under CWE-476, which specifically addresses NULL pointer dereference conditions in software implementations. The vulnerability is particularly concerning because it operates at the kernel level within the operating system's core services, meaning that successful exploitation can lead to system instability and complete denial of service. The lack of proper validation for userclient type parameters creates an execution path where the system cannot properly handle malformed input, resulting in the kernel crash and subsequent system hang.
From an operational perspective, this vulnerability presents significant risks to macOS systems, particularly in enterprise environments where Thunderbolt connectivity is frequently utilized. Attackers can leverage this flaw to cause system crashes, forcing users to restart their machines and potentially disrupting critical business operations. The local privilege requirement means that an attacker does not need elevated permissions to exploit this vulnerability, making it particularly dangerous in multi-user environments where unauthorized individuals might have access to the system. The impact extends beyond simple service disruption as the kernel-level nature of the flaw can potentially expose underlying system memory structures and create opportunities for further exploitation attempts.
Security professionals should consider this vulnerability in relation to the broader ATT&CK framework, specifically under the T1499 category of Network Share Discovery and T1059 command and scripting interpreter, as local users with access to Thunderbolt interfaces can potentially leverage this flaw to disrupt system operations. The vulnerability highlights the importance of proper input validation and defensive programming practices in kernel-level code, particularly when dealing with external hardware interfaces that must process untrusted user input. Organizations should prioritize immediate patch deployment for macOS versions affected by CVE-2015-7067, as the remediation involves updating the IOThunderboltFamily driver to properly validate userclient type parameters and prevent NULL pointer dereference conditions. Additionally, system administrators should implement monitoring solutions to detect unusual Thunderbolt-related system behavior that might indicate exploitation attempts, while maintaining comprehensive backup and recovery procedures to address potential system instability caused by this vulnerability.