CVE-2018-4193 in macOS
Summary
by MITRE
An issue was discovered in certain Apple products. macOS before 10.13.5 is affected. The issue involves the "Windows Server" component. It allows attackers to execute arbitrary code in a privileged context or cause a denial of service (memory corruption) via a crafted app.
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Analysis
by VulDB Data Team • 12/25/2024
The vulnerability identified as CVE-2018-4193 represents a critical security flaw within Apple's macOS operating system affecting versions prior to 10.13.5. This issue specifically resides within the "Windows Server" component which is part of macOS's networking infrastructure designed to support Windows file sharing protocols. The vulnerability stems from improper memory handling within the Windows Server service implementation, creating a pathway for malicious actors to exploit memory corruption flaws that could lead to arbitrary code execution or system instability. The affected Windows Server component is responsible for managing SMB (Server Message Block) protocol communications and file sharing operations between macOS systems and Windows-based networks, making it a critical element in enterprise environments where cross-platform compatibility is essential.
The technical exploitation of this vulnerability occurs through the crafting of a malicious application that triggers memory corruption within the Windows Server service when processing specific network requests or file operations. This memory corruption allows attackers to execute code with elevated privileges typically associated with system-level processes, effectively bypassing standard user permission boundaries. The flaw manifests when the Windows Server component fails to properly validate input data from network connections, particularly during file transfer operations or directory enumeration activities. Attackers can leverage this vulnerability by constructing specially crafted network requests that, when processed by the vulnerable Windows Server service, cause memory corruption that can be manipulated to execute arbitrary code within the privileged context of the operating system. This type of vulnerability aligns with CWE-121, which describes stack-based buffer overflow conditions, and CWE-122, which covers heap-based buffer overflow scenarios, both of which are common attack vectors for privilege escalation exploits.
The operational impact of CVE-2018-4193 extends beyond simple denial of service scenarios to encompass full system compromise capabilities that pose significant risks to enterprise environments. Organizations running affected macOS versions are particularly vulnerable as the attack vector can be executed remotely through network-based attacks without requiring physical access or user interaction. The privilege escalation aspect means that successful exploitation could allow attackers to gain root-level access to systems, potentially enabling them to install persistent backdoors, exfiltrate sensitive data, or disrupt critical business operations. This vulnerability is particularly concerning in corporate environments where macOS systems often serve as file servers or workstations connecting to Windows-based infrastructure, creating multiple potential attack surfaces. The memory corruption nature of the flaw also increases the risk of system crashes or reboots, potentially causing denial of service conditions that could disrupt business operations and require system restarts.
Security professionals should implement immediate mitigations including updating affected systems to macOS 10.13.5 or later versions where Apple has patched the vulnerability through proper memory validation and input sanitization. Network segmentation strategies should be employed to limit access to systems running the Windows Server service, particularly in environments where untrusted network traffic may be present. Organizations should also consider disabling the Windows Server service entirely if it is not required for business operations, following the principle of least privilege. The vulnerability demonstrates the importance of proper memory management in system services and aligns with ATT&CK technique T1055 which covers process injection and privilege escalation techniques. Additional defensive measures include implementing network monitoring to detect unusual SMB protocol activity and deploying endpoint protection solutions that can identify and block malicious network requests targeting the vulnerable Windows Server service. Regular vulnerability assessments should be conducted to identify other potentially affected system components, as this vulnerability type typically indicates broader memory safety issues within the operating system that may require additional hardening measures.