CVE-2017-2418 in macOS
Summary
by MITRE
An issue was discovered in certain Apple products. macOS before 10.12.4 is affected. The issue involves the "Hypervisor" component. It allows guest OS users to obtain sensitive information from the CR8 control register via unspecified vectors.
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Analysis
by VulDB Data Team • 10/28/2024
The vulnerability identified as CVE-2017-2418 resides within Apple's macOS operating system, specifically affecting versions prior to 10.12.4. This security flaw exists within the Hypervisor framework which serves as the foundation for virtualization capabilities in Apple's ecosystem. The issue represents a critical information disclosure vulnerability that undermines the fundamental security boundaries between host and guest operating systems in virtualized environments. The vulnerability stems from improper handling of the CR8 control register, a hardware register that plays a crucial role in managing virtual machine execution states and privilege levels.
The technical exploitation of this vulnerability occurs through the Hypervisor component's insufficient validation of guest operating system access to control registers. When a guest OS attempts to access the CR8 register, the hypervisor fails to properly enforce access restrictions that should prevent unauthorized information leakage. This flaw allows malicious guest operating systems to read sensitive data that should remain isolated within the host system's memory space. The unspecified vectors of exploitation suggest that the vulnerability can be triggered through various mechanisms within the virtualization environment, potentially including direct register manipulation or indirect access through virtualized device drivers. The CR8 register contains critical information about virtual machine execution states, including interrupt handling and privilege level management, making it a valuable target for attackers seeking to escalate privileges or extract confidential information.
The operational impact of CVE-2017-2418 extends beyond simple information disclosure, as it fundamentally compromises the security model of virtualized environments on Apple platforms. Attackers could leverage this vulnerability to gain insights into the host system's internal state, potentially enabling more sophisticated attacks such as privilege escalation or side-channel attacks against other virtual machines running on the same host. The vulnerability affects macOS systems running versions earlier than 10.12.4, which represents a significant portion of Apple's user base during that time period. This flaw particularly impacts enterprise environments where macOS virtualization is commonly used for development testing, application isolation, or legacy application support. The vulnerability also creates potential risks for users running multiple virtual machines simultaneously, as information leakage from one guest could potentially compromise other virtualized environments sharing the same physical hardware.
From a cybersecurity perspective, this vulnerability aligns with CWE-200, which addresses "Information Exposure," and represents a classic case of insufficient access control in virtualized environments. The flaw demonstrates how hypervisor security can be compromised through seemingly minor implementation gaps in control register handling. Organizations should consider this vulnerability in relation to ATT&CK techniques such as privilege escalation and information gathering, as it enables adversaries to collect sensitive data that could be used for further exploitation. The vulnerability also highlights the importance of maintaining up-to-date security patches, particularly in virtualized environments where the attack surface is expanded by the presence of multiple operating systems and virtualization layers. Security professionals should implement monitoring for suspicious virtualization activities and ensure that macOS systems are promptly updated to versions that address this specific hypervisor flaw. The incident underscores the critical need for rigorous security testing of virtualization components and proper isolation mechanisms between host and guest operating systems.