CVE-2018-4167 in macOS
Summary
by MITRE
An issue was discovered in certain Apple products. iOS before 11.3 is affected. macOS before 10.13.4 is affected. tvOS before 11.3 is affected. watchOS before 4.3 is affected. The issue involves the "File System Events" component. A race condition allows attackers to execute arbitrary code in a privileged context via a crafted app.
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Analysis
by VulDB Data Team • 02/26/2023
The vulnerability identified as CVE-2018-4167 represents a critical race condition flaw within Apple's File System Events component across multiple operating systems including iOS, macOS, tvOS, and watchOS. This issue affects versions prior to the specified security updates, creating a dangerous privilege escalation vector that could be exploited by malicious applications. The race condition occurs within the file system event handling mechanism that monitors and reports file system changes, creating a temporal window where improper synchronization allows unauthorized code execution in a privileged context.
The technical implementation of this vulnerability stems from insufficient synchronization mechanisms within the File System Events framework. When applications register for file system notifications, the underlying system must properly coordinate between different threads and processes to ensure that event delivery occurs safely. The race condition manifests when multiple processes attempt to access or modify file system event structures simultaneously without proper locking mechanisms, allowing an attacker's malicious application to manipulate the event processing flow and inject arbitrary code execution. This flaw directly maps to CWE-362, which describes a race condition vulnerability where two or more threads access shared data concurrently and at least one of the threads modifies the data, leading to unpredictable behavior.
The operational impact of CVE-2018-4167 extends beyond simple privilege escalation, as it enables attackers to gain elevated system privileges through seemingly benign applications. Once exploited, the malicious code can execute with the same privileges as the file system event monitoring processes, potentially allowing access to sensitive system resources, modification of critical system files, or establishment of persistent backdoors. The vulnerability is particularly dangerous because it operates within the core file system monitoring infrastructure, making it difficult to detect and isolate. Attackers can craft malicious applications that leverage this race condition to execute code with system-level privileges, effectively bypassing normal application sandboxing mechanisms.
Security professionals should implement immediate mitigations including deployment of the respective operating system updates that address this race condition in the File System Events component. Organizations must ensure all affected Apple devices are updated to iOS 11.3, macOS 10.13.4, tvOS 11.3, and watchOS 4.3 or later versions. Network monitoring solutions should be enhanced to detect suspicious application behavior patterns that might indicate exploitation attempts, particularly around file system event registration and processing activities. System administrators should also review application permissions and implement additional security controls to limit the potential impact of compromised applications. The vulnerability aligns with ATT&CK technique T1055.001 for privilege escalation through race conditions, making it a significant concern for enterprise security teams managing Apple device fleets.