CVE-2016-4628 in watchOS
Summary
by MITRE
IOAcceleratorFamily in Apple iOS before 9.3.3 and watchOS before 2.2.2 allows local users to obtain sensitive information from kernel memory or cause a denial of service (out-of-bounds read) via unspecified vectors.
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Analysis
by VulDB Data Team • 09/06/2022
The vulnerability identified as CVE-2016-4628 resides within the IOAcceleratorFamily component of Apple's operating systems, specifically affecting iOS versions prior to 9.3.3 and watchOS versions prior to 2.2.2. This kernel-level component is responsible for managing graphics acceleration and hardware acceleration services, making it a critical subsystem that interfaces directly with the operating system's core functionalities. The vulnerability represents a significant security flaw that could potentially expose sensitive kernel memory to unauthorized local users, creating a substantial risk for system integrity and confidentiality.
The technical flaw manifests as an out-of-bounds read condition that occurs when the IOAcceleratorFamily processes certain input data structures. This type of vulnerability typically arises from inadequate bounds checking within memory access operations, where the system fails to validate array indices or buffer sizes before accessing memory locations. The unspecified vectors suggest that multiple attack paths could trigger this condition, potentially through malformed graphics commands, memory allocation requests, or other kernel interface interactions that the IOAcceleratorFamily component handles. From a cybersecurity perspective, this vulnerability maps to CWE-125, which describes out-of-bounds read conditions, and represents a classic example of insufficient input validation at kernel level interfaces.
The operational impact of this vulnerability is substantial for local attackers who can leverage it to either extract sensitive information from kernel memory or cause system instability through denial of service conditions. When an out-of-bounds read occurs, it can potentially expose kernel memory contents including cryptographic keys, user credentials, system configuration data, or other confidential information that should remain protected within the kernel space. The denial of service aspect can lead to complete system crashes or unresponsiveness, effectively rendering the device unusable until reboot occurs. This vulnerability particularly affects mobile devices where the kernel-level graphics acceleration is heavily utilized for user interface rendering, application performance, and multimedia processing.
From an adversarial perspective, this vulnerability aligns with ATT&CK technique T1068, which involves exploiting local system privileges to gain access to sensitive information or cause system instability. Attackers with local access could potentially exploit this vulnerability to escalate their privileges or extract sensitive data from the kernel memory space. The remediation strategy involves updating to the patched versions of iOS 9.3.3 and watchOS 2.2.2, which include proper bounds checking and input validation mechanisms within the IOAcceleratorFamily component. Security professionals should also implement monitoring for anomalous kernel memory access patterns and consider device hardening measures that limit local user privileges to reduce the attack surface. Organizations should prioritize patch management for these affected Apple operating systems to prevent exploitation of this kernel-level vulnerability that could compromise device security and user privacy.