CVE-2016-4625 in Mac OS X
Summary
by MITRE
Use-after-free vulnerability in IOSurface in Apple OS X before 10.11.6 allows local users to gain privileges via unspecified vectors.
If you want to get the best quality for vulnerability data then you always have to consider VulDB.
Analysis
by VulDB Data Team • 12/11/2024
The CVE-2016-4625 vulnerability represents a critical use-after-free flaw within the IOSurface component of Apple's macOS operating system, affecting versions prior to 10.11.6. This vulnerability resides in the kernel-level subsystem responsible for managing graphics surfaces and memory allocation for graphics operations. The IOSurface framework serves as a core component in macOS graphics architecture, handling surface objects that are essential for rendering operations across various applications and system services. The vulnerability specifically manifests when the system fails to properly manage memory references after objects have been freed, creating opportunities for malicious code to exploit this memory management flaw.
The technical nature of this use-after-free vulnerability stems from improper handling of reference counting and memory deallocation within the IOSurface kernel extension. When certain graphics operations are performed, the system allocates memory for surface objects and maintains references to these allocations. However, under specific conditions, the system may free memory associated with these objects while still maintaining references to them, creating a scenario where subsequent operations attempt to access already-released memory locations. This memory corruption can be exploited by local attackers to manipulate kernel memory structures and potentially execute arbitrary code with elevated privileges. The vulnerability operates at the kernel level, making it particularly dangerous as successful exploitation can lead to complete system compromise and privilege escalation from user-level to kernel-level execution.
The operational impact of CVE-2016-4625 extends beyond simple local privilege escalation, as it provides attackers with a pathway to achieve system-wide control without requiring network access or user interaction. Attackers can leverage this vulnerability through local execution contexts, potentially using it to bypass security controls, escalate privileges to root access, and subsequently compromise the entire system. The nature of the IOSurface component means that exploitation could affect graphics-intensive applications, system services, and kernel-level operations that depend on surface management. This vulnerability aligns with CWE-416, which specifically addresses use-after-free conditions, and represents a classic example of how improper memory management in kernel components can create severe security implications. The vulnerability's classification under the attack pattern taxonomy includes techniques from the MITRE ATT&CK framework related to privilege escalation and kernel exploitation, specifically targeting the 'Exploitation for Privilege Escalation' and 'Kernel Exploitation' domains.
Mitigation strategies for CVE-2016-4625 require immediate system updates to macOS version 10.11.6 or later, which includes patches that address the memory management flaws in the IOSurface component. System administrators should prioritize deployment of these security updates across all affected systems, particularly in enterprise environments where local privilege escalation could lead to widespread compromise. Additional protective measures include implementing kernel security modules, monitoring for suspicious kernel-level activities, and applying network segmentation controls to limit the potential impact of successful exploitation. Organizations should also conduct thorough vulnerability assessments to identify systems running unsupported macOS versions and ensure comprehensive patch management processes are in place. The vulnerability demonstrates the critical importance of maintaining up-to-date system components and highlights the risks associated with legacy operating system versions that may not receive security updates. Security monitoring should focus on detecting anomalous kernel behavior, unexpected privilege escalation attempts, and unusual graphics-related system calls that could indicate exploitation attempts.