CVE-2016-7585 in macOS
Summary
by MITRE
An issue was discovered in certain Apple products. macOS before 10.12.4 is affected. The issue involves mishandling of DMA in the "EFI" component. It allows physically proximate attackers to discover the FileVault 2 encryption password via a crafted Thunderbolt adapter.
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Analysis
by VulDB Data Team • 10/27/2024
The vulnerability identified as CVE-2016-7585 represents a critical security flaw in Apple's macOS operating system affecting versions prior to 10.12.4. This weakness resides within the EFI (Extensible Firmware Interface) component of Apple's firmware architecture, specifically concerning how the system handles Direct Memory Access operations. The issue stems from insufficient protection mechanisms that fail to properly restrict memory access during Thunderbolt connections, creating a significant attack vector for physically proximate adversaries.
The technical exploitation of this vulnerability occurs through a crafted Thunderbolt adapter that can be used to perform DMA attacks against macOS systems. When a malicious Thunderbolt device is connected to an affected system, it can potentially access the system's memory and extract sensitive information including FileVault 2 encryption passwords. This occurs because the EFI firmware does not adequately validate or restrict DMA operations from external Thunderbolt devices, particularly when the system is running but locked. The flaw essentially allows attackers to bypass traditional security measures by leveraging the inherent capabilities of the Thunderbolt interface to directly access system memory without proper authentication or authorization checks.
From an operational impact perspective, this vulnerability creates a severe risk for users who may be physically compromised in environments where Thunderbolt ports are accessible to unauthorized individuals. The attack requires only physical proximity to the device and does not need network connectivity or remote access capabilities, making it particularly dangerous in corporate environments, public spaces, or any location where unauthorized individuals might gain access to a locked computer. The exposure of FileVault 2 passwords through this vector effectively neutralizes the encryption protection that users rely on to secure their data, potentially leading to complete system compromise and data theft.
The vulnerability aligns with CWE-355 and CWE-284 categories, specifically addressing inadequate protection mechanisms in firmware components and improper access control in system interfaces. This flaw also maps to several ATT&CK techniques including T1059.001 for system commands and T1003.002 for credential dumping, as attackers can extract sensitive authentication information through the DMA attack vector. Organizations should implement immediate mitigations including updating to macOS 10.12.4 or later, disabling Thunderbolt ports when not in use, implementing physical security controls to prevent unauthorized device attachment, and educating users about the risks of connecting unknown devices to their systems. The vulnerability demonstrates the critical importance of firmware security and the need for comprehensive protection mechanisms throughout the entire system architecture rather than relying solely on higher-level security controls.