CVE-2016-4775 in tvOS
Summary
by MITRE
The kernel in Apple OS X before 10.12, tvOS before 10, and watchOS before 3 allows local users to gain privileges or cause a denial of service (memory corruption) via unspecified vectors.
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Analysis
by VulDB Data Team • 09/21/2022
The vulnerability identified as CVE-2016-4775 represents a critical kernel-level flaw affecting multiple Apple operating systems including macOS versions prior to 10.12, tvOS versions before 10, and watchOS versions before 3. This issue resides within the core kernel components that manage system resources and provide fundamental operating system services, making it particularly dangerous as it operates at the most privileged level of the system architecture. The vulnerability enables local attackers to exploit memory corruption issues that can result in either privilege escalation or denial of service conditions, fundamentally compromising system integrity and availability.
The technical nature of this vulnerability stems from unspecified vectors within the kernel implementation that lead to memory corruption. Such memory corruption vulnerabilities typically arise from improper input validation, buffer overflows, or use-after-free conditions within kernel space code. The unspecified nature of the attack vectors suggests that multiple pathways could potentially trigger the same underlying memory corruption issue, making the vulnerability particularly challenging to defend against as it may be exploitable through various attack surfaces. From a cybersecurity perspective, kernel-level vulnerabilities are classified under CWE-119 Improper Access to Memory and CWE-121 Stack-based Buffer Overflow, representing the intersection of memory safety issues and privilege escalation risks.
The operational impact of CVE-2016-4775 extends beyond simple system instability as local attackers with minimal privileges can potentially leverage this flaw to achieve system compromise. When an attacker successfully exploits this vulnerability, they may gain elevated privileges to execute arbitrary code with kernel-level permissions, effectively bypassing all user-mode security controls and access restrictions. The memory corruption aspect creates a denial of service scenario that can crash the entire operating system, rendering devices unusable and potentially requiring complete system reinstallation. This dual nature of the vulnerability makes it particularly attractive to threat actors as it provides both persistent access and system disruption capabilities.
Mitigation strategies for CVE-2016-4775 primarily focus on immediate system updates and patches provided by Apple to address the kernel-level memory corruption issues. Organizations should prioritize deployment of the latest security updates for affected operating systems, particularly since this vulnerability affects widely used consumer and enterprise devices. System administrators should implement comprehensive monitoring to detect potential exploitation attempts and establish baseline system states to quickly identify compromise. The vulnerability aligns with ATT&CK technique T1068 Exploitation for Privilege Escalation and T1499 Endpoint Denial of Service, indicating that defenders must consider both privilege escalation and availability attack vectors when planning their defensive strategies. Additional protective measures include implementing kernel patch management policies, maintaining updated threat intelligence feeds, and conducting regular security assessments to identify and remediate similar vulnerabilities in the system's kernel components.