CVE-2016-4723 in macOS
Summary
by MITRE
Intel Graphics Driver in Apple OS X before 10.12 allows attackers to execute arbitrary code in a privileged context or cause a denial of service (memory corruption) via a crafted app.
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Analysis
by VulDB Data Team • 09/20/2022
The vulnerability identified as CVE-2016-4723 represents a critical security flaw within Intel Graphics Driver implementations on Apple operating systems prior to version 10.12. This issue stems from inadequate input validation and memory management within the graphics driver component that processes graphics-related requests from applications. The flaw enables attackers to craft malicious applications that can exploit the driver's handling of graphics commands, leading to potential privilege escalation or system instability. The vulnerability specifically affects the kernel-level graphics subsystem that manages hardware acceleration for display functions, creating a pathway for unauthorized code execution with elevated privileges.
Technical exploitation of this vulnerability occurs through the manipulation of graphics processing commands that are typically handled by the Intel graphics driver. When a malicious application submits crafted graphics operations, the driver fails to properly validate input parameters, leading to memory corruption that can be leveraged to execute arbitrary code within the kernel context. This memory corruption vulnerability falls under the CWE-121 category of Stack-based Buffer Overflow, though the specific implementation involves heap corruption mechanisms that allow attackers to overwrite critical memory structures. The flaw demonstrates poor memory safety practices in the graphics driver's command processing pipeline, where insufficient bounds checking and improper memory allocation handling create exploitable conditions.
The operational impact of CVE-2016-4723 extends beyond simple privilege escalation to encompass potential system compromise and denial of service conditions. Attackers can leverage this vulnerability to gain root-level access to affected systems, enabling them to install persistent backdoors, modify system files, or exfiltrate sensitive data without detection. The memory corruption aspect also creates opportunities for denial of service attacks that can crash the graphics subsystem or entire operating system, rendering affected devices unusable until system restart. This vulnerability directly aligns with ATT&CK technique T1068 for Local Privilege Escalation and T1499 for Endpoint Denial of Service, making it a particularly dangerous flaw for both offensive and defensive cybersecurity operations.
Mitigation strategies for CVE-2016-4723 primarily focus on updating to Apple macOS version 10.12 or later, which includes patches addressing the graphics driver memory handling issues. Organizations should implement application whitelisting policies to prevent execution of untrusted graphics-intensive applications, particularly those from unknown sources or with suspicious behavior patterns. System administrators should monitor for anomalous graphics processing activities that could indicate exploitation attempts, as the vulnerability requires active application execution to be effective. Additionally, implementing network-based intrusion detection systems with signatures for known exploitation patterns can help identify attempts to leverage this vulnerability. The patch released by Apple specifically addresses the memory corruption issue in the Intel graphics driver's command processing, ensuring proper input validation and memory management before any graphics commands are executed, thereby closing the privilege escalation pathway that attackers could exploit.