CVE-2017-0271 in Windows
Summary
by MITRE
Microsoft Server Message Block 1.0 (SMBv1) allows an information disclosure vulnerability in the way that Microsoft 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, 1607, and 1703, and Windows Server 2016 handles certain requests, aka "Windows SMB Information Disclosure Vulnerability". This CVE ID is unique from CVE-2017-0267, CVE-2017-0268, CVE-2017-0270, CVE-2017-0274, CVE-2017-0275, and CVE-2017-0276.
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Analysis
by VulDB Data Team • 08/21/2024
The vulnerability identified as CVE-2017-0271 represents a critical information disclosure flaw within Microsoft Server Message Block version 1.0 protocol implementation across multiple Windows operating systems. This vulnerability specifically affects 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, 1607, and 1703, as well as Windows Server 2016. The flaw manifests in how these systems process certain SMBv1 requests, creating an avenue for unauthorized information disclosure that could potentially expose sensitive system data to attackers. The vulnerability operates at the protocol level, making it particularly dangerous as it can be exploited without requiring authentication or elevated privileges, aligning with attack patterns described in the MITRE ATT&CK framework under the information gathering and credential access domains.
The technical mechanism behind this information disclosure vulnerability stems from improper handling of specific SMBv1 request structures that cause the Windows operating systems to inadvertently expose memory contents or internal system information. When processing malformed or specially crafted SMBv1 requests, the affected systems fail to properly validate input parameters, leading to memory leaks or information exposure that can reveal system internals, configuration details, or potentially sensitive data from system memory. This type of vulnerability falls under CWE-200, which specifically addresses "Information Exposure" and represents a classic example of how improper input validation can lead to unintended information disclosure. The vulnerability's impact is amplified by the widespread use of SMBv1 across enterprise environments, making it a prime target for reconnaissance activities and subsequent exploitation attempts.
The operational impact of CVE-2017-0271 extends beyond simple information disclosure, as the exposed data could potentially provide attackers with valuable intelligence for planning more sophisticated attacks. The vulnerability's presence in multiple Windows versions creates a broad attack surface that security teams must address comprehensively, particularly in environments where SMBv1 remains enabled for legacy application compatibility. This information exposure could enable attackers to gather system fingerprints, network configurations, or other sensitive details that would otherwise remain protected. Organizations may find that their security posture is weakened by the presence of this vulnerability, as it provides attackers with additional reconnaissance capabilities that can be leveraged in conjunction with other exploits or attack vectors, potentially leading to privilege escalation or further system compromise.
Mitigation strategies for CVE-2017-0271 should prioritize the complete disablement of SMBv1 across all affected systems, as this protocol version has known security limitations and is no longer recommended for use in modern network environments. Microsoft has provided specific guidance for disabling SMBv1 through registry modifications and group policy configurations, which should be implemented immediately across all affected systems. Additionally, organizations should conduct comprehensive vulnerability assessments to identify any remaining SMBv1 implementations within their network infrastructure, as the vulnerability can be exploited through various attack vectors including network scanning and targeted reconnaissance. Network segmentation and firewall rules should be configured to block SMBv1 traffic at the network perimeter, while security monitoring should be enhanced to detect anomalous SMBv1 activity that might indicate exploitation attempts. The remediation process should also include verification of system configurations through automated scanning tools to ensure that the vulnerability has been properly addressed and that no residual exposure exists within the organization's computing environment.