CVE-2018-0749 in Windows
Summary
by MITRE
The Microsoft Server Message Block (SMB) Server in Windows 7 SP1, Windows 8.1 and RT 8.1, Windows Server 2008 SP2 and R2 SP1, Windows Server 2012 and R2, Windows 10 Gold, 1511, 1607, 1703 and 1709, Windows Server 2016 and Windows Server, version 1709 allows an elevation of privilege vulnerability due to the way SMB Server handles specially crafted files, aka "Windows Elevation of Privilege Vulnerability".
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Analysis
by VulDB Data Team • 09/16/2025
The vulnerability identified as CVE-2018-0749 represents a critical elevation of privilege flaw within Microsoft's Server Message Block protocol implementation across multiple Windows operating systems. This vulnerability affects Windows 7 SP1, Windows 8.1, Windows Server 2008 SP2 and R2 SP1, Windows Server 2012 and R2, Windows 10 versions from Gold through 1709, and Windows Server 2016. The flaw specifically resides in how the SMB server component processes specially crafted files, creating an avenue for malicious actors to escalate their privileges within the targeted system. This vulnerability operates at the kernel level, making it particularly dangerous as it can allow attackers to gain system-level access and execute arbitrary code with the highest possible privileges.
The technical mechanism behind this vulnerability involves the improper handling of file operations within the SMB server implementation. When the SMB server receives specially crafted file requests or handles file operations with malformed parameters, it fails to properly validate input data, leading to memory corruption that can be exploited to execute arbitrary code. This type of vulnerability falls under CWE-121, which describes stack-based buffer overflow conditions, and more specifically relates to improper input validation within server-side components. The vulnerability enables attackers to manipulate the SMB server's internal state through crafted file operations, potentially leading to privilege escalation from a standard user account to SYSTEM level access.
The operational impact of CVE-2018-0749 is severe and far-reaching, as it allows remote attackers to achieve privilege escalation without requiring authentication or specific user interaction. Once exploited, this vulnerability can provide attackers with complete control over affected systems, enabling them to install malware, modify system files, access sensitive data, and potentially establish persistent backdoors. The vulnerability is particularly concerning because it affects multiple versions of Windows that remain in widespread use across enterprise environments, creating a broad attack surface. The exploitation can occur through network-based attacks, making it possible for attackers to compromise systems remotely without physical access or user interaction.
Security professionals should implement immediate mitigation strategies including applying the relevant Microsoft security updates, which address this vulnerability through proper input validation and memory handling improvements. Network segmentation and firewall rules should be configured to restrict SMB traffic where possible, particularly at the perimeter of network environments. Monitoring for unusual SMB traffic patterns and file operations can help detect potential exploitation attempts. Organizations should also consider disabling SMBv1 if not required for legacy system compatibility, as this protocol version is more susceptible to various attacks. The mitigation aligns with ATT&CK technique T1068, which covers 'Exploitation for Privilege Escalation', and emphasizes the importance of patch management and network security controls to prevent exploitation of such vulnerabilities.