CVE-2019-8529 in macOS
Summary
by MITRE
A memory corruption issue was addressed with improved input validation. This issue is fixed in iOS 12.2, macOS Mojave 10.14.4. An application may be able to execute arbitrary code with kernel privileges.
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Analysis
by VulDB Data Team • 08/08/2023
This vulnerability represents a critical memory corruption flaw that existed in Apple's operating systems prior to the release of iOS 12.2 and macOS Mojave 10.14.4. The issue stems from insufficient input validation mechanisms within the kernel-level components of these operating systems, creating a pathway for malicious applications to exploit memory handling weaknesses. The vulnerability falls under the category of kernel-level privilege escalation, where a malicious application could potentially gain unauthorized access to kernel privileges through carefully crafted inputs that trigger memory corruption conditions. This type of vulnerability is particularly dangerous because it operates at the core level of system security, bypassing standard user-space protections and access controls that typically prevent unauthorized code execution.
The technical implementation of this flaw involves improper validation of input data structures that are processed by kernel components responsible for system resource management and memory allocation. When an application provides malformed or unexpected input to kernel functions, the memory corruption occurs in a manner that can be manipulated to redirect execution flow or overwrite critical kernel data structures. This memory corruption vulnerability aligns with CWE-121, which describes stack-based buffer overflow conditions, and CWE-122, which covers heap-based buffer overflow scenarios that can lead to arbitrary code execution. The vulnerability's exploitation requires a sophisticated understanding of memory layout and kernel operation, making it particularly challenging for attackers to successfully leverage without proper system context knowledge.
The operational impact of CVE-2019-8529 extends beyond simple privilege escalation to encompass potential system compromise and complete control over affected devices. An attacker who successfully exploits this vulnerability could execute arbitrary code with the highest system privileges, effectively bypassing all standard security mechanisms including sandboxing, code signing, and access controls. This capability allows for persistent system compromise, data exfiltration, and the installation of additional malicious payloads that can operate undetected within the kernel space. The vulnerability's presence in widely deployed operating systems means that any device running affected versions of iOS or macOS could be at risk, creating a significant attack surface for threat actors targeting enterprise environments and individual users alike. The exploitation pattern aligns with ATT&CK technique T1068, which describes 'Exploitation for Privilege Escalation', and T1059, covering 'Command and Scripting Interpreter', as the compromised system could be used to execute further malicious activities.
The remediation for this vulnerability required Apple to implement enhanced input validation mechanisms within kernel components responsible for processing user-supplied data. The fix involved strengthening memory handling routines to properly validate all inputs before processing, implementing additional bounds checking, and ensuring proper memory allocation and deallocation practices. System administrators and users should immediately update to iOS 12.2 or macOS Mojave 10.14.4 to mitigate this risk, as these versions contain the necessary patches to address the underlying memory corruption conditions. Organizations should conduct comprehensive vulnerability assessments to identify any systems running affected versions and implement patch management procedures to ensure all devices receive the necessary security updates. The vulnerability serves as a reminder of the critical importance of kernel-level security and the potential consequences when input validation mechanisms fail to properly protect system resources from malicious manipulation.