CVE-2018-4166 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 "NSURLSession" 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 • 02/07/2021
The vulnerability identified as CVE-2018-4166 represents a critical race condition flaw within Apple's NSURLSession component that affects multiple operating systems including iOS, macOS, tvOS, and watchOS. This security weakness stems from improper synchronization mechanisms within the network request handling system, creating opportunities for malicious actors to exploit temporal inconsistencies in the code execution flow. The vulnerability specifically impacts versions prior to the security updates mentioned, leaving millions of devices exposed to potential exploitation.
The technical implementation of this race condition occurs within the NSURLSession framework where concurrent access to shared resources creates unpredictable execution paths. Attackers can craft malicious applications that manipulate the timing of network operations to trigger the race condition, which ultimately leads to privilege escalation and arbitrary code execution. This flaw operates at the kernel level, allowing malicious code to run with elevated privileges typically reserved for system processes, effectively bypassing standard security boundaries that protect user data and system integrity.
The operational impact of CVE-2018-4166 extends beyond simple data theft or service disruption, as it enables full system compromise through privilege escalation. An attacker who successfully exploits this vulnerability can gain root-level access to affected devices, potentially leading to complete device takeover, data exfiltration, and persistent backdoor installation. The race condition nature makes detection particularly challenging since it relies on precise timing and system state conditions that may not manifest consistently during normal operation. This vulnerability directly maps to CWE-362, which specifically addresses race conditions in concurrent programming environments, and aligns with ATT&CK technique T1059 for command and scripting interpreter usage.
Mitigation strategies for this vulnerability require immediate deployment of Apple's security patches, specifically iOS 11.3, macOS 10.13.4, tvOS 11.3, and watchOS 4.3 updates. Organizations should implement comprehensive device management policies to ensure all affected systems receive updates promptly. Network monitoring solutions should be enhanced to detect unusual network behavior patterns that might indicate exploitation attempts. Additionally, security teams should conduct thorough risk assessments of their mobile device environments and consider implementing additional security controls such as mobile device management solutions and endpoint protection platforms to provide layered defense against similar vulnerabilities. The remediation process must include verification of patch deployment across all affected platforms and continuous monitoring for potential exploitation attempts.