CVE-2019-6221 in macOS
Summary
by MITRE
An out-of-bounds read was addressed with improved bounds checking. This issue is fixed in iOS 12.1.3, macOS Mojave 10.14.3, iTunes 12.9.3 for Windows. A malicious application may be able to elevate privileges.
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Analysis
by VulDB Data Team • 07/03/2023
This vulnerability represents a critical out-of-bounds read flaw that exists within Apple's operating systems and software ecosystem. The issue stems from inadequate bounds checking mechanisms that fail to properly validate memory access boundaries during application execution. Such vulnerabilities typically arise when developers do not sufficiently validate input parameters or memory addresses before accessing array elements or buffer regions, creating opportunities for unauthorized code execution. The vulnerability affects multiple platforms including iOS 12.1.2 and earlier versions, macOS Mojave 10.14.2 and earlier, and specific Windows versions of iTunes 12.9.2 and earlier, indicating a widespread impact across Apple's product portfolio. The flaw specifically allows for privilege escalation, meaning that a malicious application could potentially leverage this vulnerability to gain elevated system privileges beyond its normal operational scope. This type of vulnerability directly aligns with CWE-129, which describes improper validation of array index bounds, and represents a classic example of how memory safety issues can lead to severe privilege escalation attacks. The vulnerability's classification as a privilege escalation vector places it within ATT&CK technique T1068, which focuses on exploiting legitimate credentials and privileges to gain unauthorized access to system resources.
The technical implementation of this vulnerability involves scenarios where an application accesses memory locations beyond the allocated buffer boundaries, potentially reading sensitive data from adjacent memory regions or causing system instability. When bounds checking is insufficient, attackers can craft malicious inputs that trigger memory access violations, which may then be exploited to execute arbitrary code with elevated privileges. The fix implemented by Apple in iOS 12.1.3, macOS Mojave 10.14.3, and iTunes 12.9.3 demonstrates the company's approach to addressing such issues through enhanced memory validation mechanisms. These improvements typically involve implementing more robust input validation, adding additional boundary checks, and ensuring that all memory access operations are properly constrained within valid address ranges. The privilege escalation capability indicates that the vulnerability may allow an attacker to bypass normal security controls, potentially enabling access to system-level resources that should be restricted to authorized users only. This could include access to sensitive system files, kernel memory regions, or administrative functions that are normally protected from regular user applications. The remediation approach taken by Apple likely involves strengthening the underlying memory management subsystems and ensuring that all buffer operations are properly validated before execution.
The operational impact of this vulnerability extends beyond simple data corruption or application crashes, as it fundamentally compromises system integrity and security posture. Organizations running affected systems face significant risk of unauthorized access, data breaches, or complete system compromise, particularly in environments where users may be tricked into installing malicious applications. The privilege escalation nature means that even sandboxed applications could potentially gain root access, undermining the fundamental security model of modern operating systems. This vulnerability particularly affects enterprise environments where Apple products are extensively deployed, as it could enable attackers to establish persistent access to corporate networks or sensitive data repositories. Security teams must consider this vulnerability as part of their comprehensive threat landscape assessment, particularly when evaluating the risk of zero-day exploits in their environments. The vulnerability's presence in both mobile and desktop operating systems indicates that attackers could potentially use it across multiple attack vectors, including mobile device exploitation, desktop application attacks, or cross-platform persistence mechanisms. Organizations should prioritize immediate patch deployment to protect against potential exploitation attempts, while also implementing monitoring for suspicious privilege escalation activities that may indicate successful exploitation of this vulnerability. The fix addresses the root cause by implementing more rigorous bounds checking procedures that prevent memory access violations and maintain proper system integrity during normal application execution.