CVE-2017-0143 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-2017-0144, CVE-2017-0145, CVE-2017-0146, and CVE-2017-0148.
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Analysis
by VulDB Data Team • 12/26/2024
The vulnerability identified as CVE-2017-0143 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 resides in how the SMBv1 server component processes crafted network packets, creating a pathway for remote attackers to execute arbitrary code on affected systems without requiring authentication. This vulnerability operates at the protocol level, making it particularly dangerous as it can be exploited across network boundaries without the need for valid credentials or user interaction.
The technical exploitation of CVE-2017-0143 occurs through the manipulation of SMBv1 packets that trigger a buffer overflow condition within the server implementation. The vulnerability stems from insufficient input validation and memory management within the SMBv1 server component, allowing attackers to craft malicious packets that overwrite memory locations and potentially redirect execution flow. This particular flaw falls under the Common Weakness Enumeration category CWE-121, which addresses stack-based buffer overflow conditions, and more specifically relates to CWE-787, which covers out-of-bounds writes. The vulnerability enables attackers to achieve privilege escalation and system compromise through carefully constructed network traffic that exploits the protocol's handling of malformed SMB requests. The attack vector is network-based, requiring only that the target system be accessible via SMBv1 protocol, making it particularly prevalent in enterprise environments where SMBv1 remains enabled.
The operational impact of CVE-2017-0143 extends far beyond individual system compromise, as it provides attackers with a means to establish persistent access and potentially move laterally within network environments. When exploited successfully, this vulnerability allows attackers to execute code with the privileges of the target system, often resulting in full system compromise and potential access to sensitive data and network resources. The vulnerability's significance is amplified by the widespread use of SMBv1 in enterprise networks, where legacy systems and poorly configured firewalls may leave systems exposed to exploitation. Organizations running affected versions of Windows are particularly vulnerable, as the default configuration often enables SMBv1 support, creating a persistent attack surface that attackers can leverage for reconnaissance and exploitation. The vulnerability's relationship to the broader WannaCry ransomware outbreak demonstrates how such flaws can be weaponized at scale, affecting thousands of systems globally.
Mitigation strategies for CVE-2017-0143 primarily focus on disabling SMBv1 protocol support, which represents the most effective immediate solution. Microsoft recommends disabling SMBv1 through registry modifications or group policy configurations, as this protocol is considered inherently insecure and has been deprecated in favor of SMBv2 and later versions. Organizations should also ensure that all systems are patched with the relevant security updates released by Microsoft, particularly the July 2017 security updates that addressed this vulnerability. Network segmentation and firewall rules should be implemented to restrict SMB traffic to necessary internal communications only, while monitoring systems should be configured to detect unusual SMBv1 traffic patterns. Additionally, implementing network intrusion detection systems and configuring endpoint protection solutions can help identify and prevent exploitation attempts. The ATT&CK framework categorizes this vulnerability under T1075, which addresses "Pass the Hash" and related credential theft techniques, highlighting the potential for attackers to leverage this vulnerability as part of broader attack chains that may include credential harvesting and lateral movement phases.