CVE-2016-4725 in tvOS
Summary
by MITRE
IOAcceleratorFamily in Apple iOS before 10, OS X before 10.12, tvOS before 10, and watchOS before 3 allows remote attackers to obtain sensitive information from process memory or cause a denial of service (memory corruption) via a crafted web site.
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Analysis
by VulDB Data Team • 09/21/2022
The vulnerability identified as CVE-2016-4725 resides within the IOAcceleratorFamily component of Apple's operating systems, affecting iOS versions prior to 10, macOS versions prior to 10.12, tvOS versions prior to 10, and watchOS versions prior to 3. This flaw represents a critical security weakness in the kernel-level graphics acceleration framework that handles hardware acceleration for graphics processing. The vulnerability stems from improper input validation and memory management within the IOAcceleratorFamily driver, which is responsible for managing graphics processing unit acceleration capabilities. The issue manifests when the system processes specially crafted web content that triggers memory corruption within the graphics acceleration subsystem. This vulnerability operates at the intersection of kernel memory management and web rendering, creating a dangerous attack surface where malicious web content can directly influence kernel memory structures. The underlying technical flaw involves insufficient bounds checking and memory validation when processing graphics acceleration requests from user-space applications, particularly web browsers that utilize hardware acceleration features.
The operational impact of CVE-2016-4725 extends beyond simple information disclosure to encompass potential system compromise through memory corruption attacks. Attackers can leverage this vulnerability by hosting malicious web content that, when rendered by a vulnerable browser, triggers the flawed IOAcceleratorFamily code path. The memory corruption can result in arbitrary code execution within kernel space, potentially allowing attackers to escalate privileges and gain full system control. The vulnerability's remote exploitability means that attackers do not require physical access to the device or local network presence to carry out attacks. This characteristic aligns with attack patterns documented in the MITRE ATT&CK framework under the T1068 technique for local privilege escalation and T1203 for exploitation for execution. The specific nature of the flaw makes it particularly dangerous as it bridges the gap between web browsing and kernel-level operations, creating a direct pathway for remote code execution. The memory corruption can manifest in various forms including heap corruption, stack overflow, or use-after-free conditions that can be exploited to gain unauthorized access to system resources.
The security implications of this vulnerability extend to the broader mobile and desktop computing landscape, as it affects multiple Apple platforms and represents a fundamental flaw in the graphics acceleration stack. Organizations and individuals using affected versions of Apple operating systems face significant risk from this vulnerability, as it can be exploited through standard web browsing activities without any user interaction beyond visiting a malicious website. The vulnerability's presence in the IOAcceleratorFamily component demonstrates how graphics acceleration features, while beneficial for performance, can introduce complex security risks when not properly isolated from user-space processes. The flaw violates fundamental security principles related to memory safety and privilege separation, as it allows untrusted web content to corrupt kernel memory structures. This vulnerability also highlights the importance of proper input validation and memory management in kernel-level components, as outlined in CWE-125 for out-of-bounds read and CWE-787 for out-of-bounds write conditions. The impact is particularly severe given that Apple's operating systems are widely deployed across enterprise and consumer environments, making this vulnerability attractive to threat actors seeking broad exploitation capabilities. Organizations should prioritize patch management and system updates to address this vulnerability, as it represents a critical security gap that can be exploited for persistent system compromise.
The mitigation strategies for CVE-2016-4725 primarily focus on applying official security updates from Apple that address the memory corruption issues within IOAcceleratorFamily. System administrators should immediately deploy the relevant patches for iOS 10, macOS 10.12, tvOS 10, and watchOS 3 to remediate the vulnerability. Additionally, network administrators can implement web filtering solutions to block access to known malicious domains that may host exploit code for this vulnerability. The implementation of security monitoring solutions that can detect anomalous memory access patterns or graphics acceleration usage may help identify potential exploitation attempts. Organizations should also consider implementing additional security controls such as web application firewalls and network segmentation to limit the potential impact of successful exploitation attempts. The vulnerability's classification as a remote code execution flaw necessitates comprehensive network security measures beyond simple patching, including endpoint protection solutions that can detect and prevent exploitation attempts. Security teams should also conduct vulnerability assessments to identify systems running affected versions of Apple operating systems and prioritize remediation efforts accordingly. The remediation process should include not only applying patches but also reviewing system configurations to ensure that hardware acceleration features are properly isolated from untrusted content sources.