CVE-2016-4773 in tvOS
Summary
by MITRE
The kernel in Apple iOS before 10, OS X before 10.12, tvOS before 10, and watchOS before 3 allows attackers to obtain sensitive memory-layout information or cause a denial of service (out-of-bounds read) via a crafted app, a different vulnerability than CVE-2016-4774 and CVE-2016-4776.
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Analysis
by VulDB Data Team • 09/21/2022
This vulnerability resides within the kernel of Apple's operating systems, specifically affecting iOS versions prior to 10, OS X versions prior to 10.12, tvOS versions prior to 10, and watchOS versions prior to 3. The flaw manifests as an out-of-bounds read condition that occurs when processing crafted applications, enabling attackers to extract sensitive memory layout information or trigger denial of service scenarios. Such vulnerabilities in kernel space represent critical security risks as they can potentially be exploited to escalate privileges and gain deeper system access. The vulnerability is classified under CWE-125 as an out-of-bounds read, which falls within the broader category of memory safety issues that have historically been primary attack vectors for sophisticated exploitation campaigns. The technical implementation involves improper bounds checking during memory operations, where the kernel fails to validate input parameters from malicious applications before attempting to access memory regions beyond allocated boundaries. This particular vulnerability demonstrates the complexity of kernel-level security where a single flawed memory access operation can compromise system integrity and potentially expose sensitive information about the memory layout of the operating system. The impact extends beyond simple denial of service as the ability to extract memory layout information provides adversaries with crucial intelligence for developing more sophisticated attacks. The vulnerability's relationship to other CVEs such as CVE-2016-4774 and CVE-2016-4776 indicates a pattern of similar kernel-level memory safety issues affecting Apple's operating systems during this timeframe. From an operational perspective, this vulnerability aligns with ATT&CK technique T1059 for command and control through application execution, and T1068 for privilege escalation via kernel exploits. The out-of-bounds read condition creates a pathway for information disclosure that can be leveraged to bypass security mitigations such as address space layout randomization. The memory layout information obtained through this vulnerability can be particularly valuable for attackers attempting to exploit other vulnerabilities or developing return-oriented programming payloads. Mitigation strategies should focus on immediate patch deployment across all affected platforms, as well as implementing monitoring for suspicious application behavior that might indicate exploitation attempts. Additionally, system administrators should consider implementing application whitelisting policies and regular security assessments to identify potential exploitation vectors. The vulnerability highlights the importance of comprehensive memory safety testing and the need for robust input validation mechanisms in kernel-level code to prevent similar issues from emerging in future releases.