CVE-2017-0146 in Windows
Summary
by MITRE
The SMBv1 server in Microsoft Windows Vista SP2; Windows Server 2008 SP2 and R2 SP1; Windows 7 SP1; Windows 8.1; Windows Server 2012 Gold and R2; Windows RT 8.1; and Windows 10 Gold, 1511, and 1607; and Windows Server 2016 allows remote attackers to execute arbitrary code via crafted packets, aka "Windows SMB Remote Code Execution Vulnerability." This vulnerability is different from those described in CVE-2017-0143, CVE-2017-0144, CVE-2017-0145, and CVE-2017-0148.
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Analysis
by VulDB Data Team • 02/04/2025
The vulnerability identified as CVE-2017-0146 represents a critical remote code execution flaw within the Server Message Block version 1 protocol implementation in multiple Microsoft Windows operating systems. This vulnerability specifically affects Windows Vista SP2, Windows Server 2008 SP2 and R2 SP1, Windows 7 SP1, Windows 8.1, Windows Server 2012 Gold and R2, Windows RT 8.1, Windows 10 Gold, 1511, and 1607, as well as Windows Server 2016. The flaw enables remote attackers to execute arbitrary code on affected systems through specially crafted SMBv1 packets, making it a significant threat to enterprise network security. The vulnerability operates at the protocol level, leveraging weaknesses in how Windows processes SMBv1 requests, particularly when handling malformed or specially constructed data packets that trigger buffer overflows or other memory corruption conditions.
The technical implementation of this vulnerability stems from improper input validation within the SMBv1 server component, which fails to adequately sanitize incoming packets before processing them. When a maliciously crafted SMBv1 packet is received, the vulnerable Windows system processes it without sufficient boundary checking, leading to memory corruption that can be exploited to overwrite critical memory locations. This type of vulnerability falls under CWE-121, which describes stack-based buffer overflow conditions, and may also relate to CWE-122, heap-based buffer overflow, depending on the specific memory corruption pattern. The exploitation typically involves crafting packets that cause the system to allocate insufficient memory for processing, resulting in buffer overflows that can be leveraged to inject and execute malicious code with the privileges of the affected service account.
From an operational perspective, this vulnerability presents a severe risk to organizations as it enables attackers to gain remote code execution capabilities without requiring authentication, making it particularly dangerous in network environments where SMB services are exposed to untrusted networks. The attack surface is extensive given the widespread adoption of Windows operating systems across enterprise environments, and the vulnerability can be exploited through various attack vectors including network-based scanning, malicious file sharing, or lateral movement within compromised networks. The impact extends beyond individual system compromise to potentially enable full network infiltration, as attackers can leverage the initial compromise to establish persistent access and move laterally through the network infrastructure. This vulnerability aligns with ATT&CK technique T1075, which describes the use of legitimate credentials for lateral movement, and T1059, which covers command and scripting interpreter usage, as attackers can leverage the executed code to establish further footholds.
Organizations should implement immediate mitigations including disabling SMBv1 protocol support on all affected systems, as this protocol is inherently insecure and has been deprecated by Microsoft. The recommended approach involves configuring Group Policy settings to disable SMBv1 client and server components, implementing network segmentation to restrict SMB traffic, and deploying intrusion detection systems to monitor for suspicious SMBv1 activity. Additionally, administrators should ensure that all affected systems receive the relevant security updates from Microsoft, particularly the patches released as part of the April 2017 security updates, which address the specific memory corruption vulnerabilities in the SMBv1 implementation. Network administrators should also consider implementing firewall rules to block SMB traffic on ports 139 and 445 from untrusted networks, and conduct thorough vulnerability assessments to identify any systems that may still be running SMBv1 services. The mitigation strategy should also include monitoring for exploitation attempts and establishing incident response procedures to quickly address any successful exploitation attempts.