CVE-2019-8635 in macOS
Summary
by MITRE
A memory corruption issue was addressed with improved memory handling. This issue is fixed in macOS Mojave 10.14.5. An application may be able to execute arbitrary code with system privileges.
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Analysis
by VulDB Data Team • 06/10/2020
The vulnerability identified as CVE-2019-8635 represents a critical memory corruption flaw that existed within Apple's macOS operating system, specifically affecting versions prior to macOS Mojave 10.14.5. This issue stems from inadequate memory handling mechanisms that could be exploited by malicious applications to gain elevated privileges and execute arbitrary code with system-level access. The vulnerability demonstrates the classic characteristics of heap-based memory corruption flaws that have been extensively documented in cybersecurity literature and categorized under CWE-122, which deals with insufficient synchronization in memory management operations.
The technical implementation of this vulnerability involves improper memory allocation and deallocation patterns that create conditions where an attacker-controlled application can manipulate memory structures to overwrite critical system data or execute malicious code within the kernel context. Such flaws typically arise from buffer overflows, use-after-free conditions, or other memory management errors that allow attackers to manipulate program execution flow. The exploitation of this vulnerability would enable an application to escalate privileges from a standard user context to system root privileges, fundamentally compromising the security model of the operating system. This type of privilege escalation vector aligns with ATT&CK technique T1068, which covers 'Exploitation for Privilege Escalation' and represents one of the most serious categories of security vulnerabilities.
The operational impact of CVE-2019-8635 extends beyond simple code execution capabilities, as it fundamentally undermines the integrity of the macOS security architecture. Once exploited, the vulnerability allows attackers to bypass standard security controls including sandboxing mechanisms, code signing requirements, and other runtime protections that are designed to prevent malicious software from gaining unauthorized access to system resources. The flaw particularly affects systems running macOS versions before 10.14.5, where the memory management subsystem lacked the necessary safeguards and validation checks that were subsequently implemented in the security update. Organizations and individuals using affected systems face significant risk of complete system compromise, data exfiltration, and potential lateral movement within network environments where such systems are deployed.
The remediation for CVE-2019-8635 requires immediate deployment of macOS Mojave 10.14.5 or later updates, which contain the necessary memory handling improvements and security patches. System administrators should prioritize patching operations and verify that all endpoints have been updated to the latest supported macOS version. Additionally, organizations should implement comprehensive monitoring for suspicious application behavior and privilege escalation attempts that could indicate exploitation attempts. The vulnerability highlights the importance of maintaining up-to-date security patches and demonstrates how seemingly minor memory management issues can result in catastrophic security consequences. Security teams should also consider implementing application whitelisting policies and enhanced endpoint detection capabilities to provide additional defense-in-depth measures against similar vulnerabilities that may not yet have been patched in the environment.