CVE-2016-4627 in tvOS
Summary
by MITRE
IOAcceleratorFamily in Apple iOS before 9.3.3, tvOS before 9.2.2, and watchOS before 2.2.2 allows local users to gain privileges or cause a denial of service (NULL pointer dereference) via unspecified vectors.
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Analysis
by VulDB Data Team • 09/06/2022
The vulnerability identified as CVE-2016-4627 resides within the IOAcceleratorFamily component of Apple's operating systems, affecting iOS versions prior to 9.3.3, tvOS prior to 9.2.2, and watchOS prior to 2.2.2. This flaw represents a critical security weakness in Apple's graphics and compute acceleration framework that handles hardware acceleration for various system operations. The IOAcceleratorFamily serves as a core component in Apple's hardware acceleration architecture, enabling efficient processing of graphics and compute tasks through dedicated hardware acceleration units. The vulnerability manifests as a NULL pointer dereference condition that can be exploited by local attackers to either escalate privileges or trigger a system denial of service. This type of vulnerability falls under the CWE-476 category of NULL Pointer Dereference, which is classified as a common weakness in software security implementations. The flaw demonstrates a fundamental programming error where the system fails to properly validate pointer references before attempting to access memory locations, creating an exploitable condition that can be leveraged for privilege escalation or system instability.
The operational impact of this vulnerability extends beyond simple denial of service scenarios, as local attackers with minimal privileges can potentially leverage the NULL pointer dereference to execute arbitrary code with elevated privileges. This represents a significant escalation risk since the IOAcceleratorFamily component operates with high system privileges and is integral to the device's core functionality. The vulnerability's exploitation potential is heightened by the fact that it occurs within a system component that is frequently accessed during normal device operations, making it an attractive target for malicious actors seeking to establish persistent access or cause system-wide disruptions. Attackers can potentially trigger the vulnerability through legitimate system calls or by manipulating the acceleration framework's memory management routines, leading to either system crashes or unauthorized privilege elevation. The timing of the vulnerability's exploitation is particularly concerning as it affects devices that are actively in use and may be running applications that utilize hardware acceleration features.
From a cybersecurity perspective, this vulnerability aligns with ATT&CK technique T1068 which covers "Exploitation for Privilege Escalation" and T1499 which addresses "Endpoint Denial of Service." The vulnerability's impact on device security posture is substantial as it provides attackers with a potential pathway to compromise the integrity and availability of Apple devices. Organizations and individuals using affected versions of Apple's operating systems face elevated risk of unauthorized access, data compromise, or system instability. The vulnerability's presence in multiple Apple operating systems demonstrates the widespread impact potential and highlights the importance of timely patch management. Security professionals should consider this vulnerability when conducting risk assessments for Apple device environments, particularly in enterprise settings where device security is paramount. The vulnerability's classification as a local privilege escalation vector means that even users with basic system access can potentially leverage this flaw to gain elevated system privileges, making it a particularly dangerous weakness in Apple's security architecture.
Mitigation strategies for CVE-2016-4627 primarily focus on immediate remediation through official Apple security updates and patches. System administrators should prioritize deployment of iOS 9.3.3, tvOS 9.2.2, and watchOS 2.2.2 updates to address the vulnerability. Additionally, organizations should implement monitoring solutions to detect potential exploitation attempts targeting this specific vulnerability. Network segmentation and access controls can help limit the potential impact if an attacker were to successfully exploit the vulnerability. The vulnerability's nature as a NULL pointer dereference suggests that defensive coding practices and runtime protections could help mitigate exploitation attempts, though the most effective solution remains the official security patches provided by Apple. Security teams should also consider implementing device management policies that enforce automatic update deployment to ensure timely remediation across all affected systems. Regular security assessments and vulnerability scanning should include checks for this specific vulnerability to maintain comprehensive security coverage for Apple device environments.