CVE-2019-8540 in macOS
Summary
by MITRE
A memory initialization issue was addressed with improved memory handling. This issue is fixed in iOS 12.2, macOS Mojave 10.14.4, tvOS 12.2, watchOS 5.2. A malicious application may be able to determine kernel memory layout.
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Analysis
by VulDB Data Team • 06/09/2024
The vulnerability identified as CVE-2019-8540 represents a memory initialization flaw that affects multiple Apple operating systems including iOS 12.1 and earlier versions, macOS Mojave 10.14.3 and earlier, tvOS 12.1 and earlier, and watchOS 5.1 and earlier. This issue stems from inadequate memory handling practices during the initialization phase of kernel memory structures, creating potential information disclosure risks that could be exploited by malicious actors. The vulnerability falls under the category of memory safety issues and aligns with CWE-1277 which specifically addresses improper initialization of memory in kernel space.
The technical flaw manifests when applications attempt to access kernel memory regions without proper initialization, potentially exposing memory layout information to unauthorized processes. This memory initialization issue allows a malicious application to determine kernel memory layout through carefully crafted memory access patterns and information leakage techniques. The vulnerability exploits the lack of proper bounds checking and memory initialization protocols that should occur during kernel memory allocation processes, creating a pathway for information disclosure attacks that could be leveraged in conjunction with other exploitation techniques.
The operational impact of this vulnerability extends beyond simple information disclosure, as it could enable attackers to bypass security mitigations and conduct more sophisticated attacks. An attacker with a malicious application could potentially use this information to craft more effective exploits against the kernel, particularly when combined with other vulnerabilities or attack vectors. The exposure of kernel memory layout information provides attackers with crucial insights into memory organization that could be used to predict memory locations, bypass address space layout randomization, or develop more precise exploitation techniques. This vulnerability particularly affects systems where privilege separation is critical for maintaining security boundaries between user space and kernel space operations.
Apple addressed this vulnerability through comprehensive memory handling improvements in the aforementioned system updates, which include enhanced memory initialization protocols, stricter memory access controls, and improved kernel memory management routines. The mitigations implemented in iOS 12.2, macOS Mojave 10.14.4, tvOS 12.2, and watchOS 5.2 focus on strengthening the memory initialization process and ensuring proper memory allocation procedures are followed during kernel operations. These updates align with ATT&CK technique T1068 which covers exploit for privilege escalation, as the vulnerability could potentially be leveraged to gain elevated privileges through kernel memory manipulation. Organizations should prioritize deployment of these security updates to mitigate the risk of exploitation and maintain system integrity against potential kernel-level attacks that could compromise the entire operating system.