CVE-2017-0212 in Windows
Summary
by MITRE
Windows Hyper-V allows an elevation of privilege vulnerability when Microsoft Windows 10 Gold, 1511, 1607, and 1703, and Windows Server 2016 fail to properly validate vSMB packet data, aka "Windows Hyper-V vSMB Elevation of Privilege Vulnerability".
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Analysis
by VulDB Data Team • 12/23/2020
The Windows Hyper-V vSMB elevation of privilege vulnerability represents a critical security flaw affecting multiple Windows operating systems including Windows 10 versions 1511, 1607, and 1703, as well as Windows Server 2016. This vulnerability specifically targets the virtualized SMB (Server Message Block) implementation within Hyper-V environments, creating a pathway for malicious actors to escalate their privileges from standard user level to system level access. The flaw stems from improper validation of vSMB packet data, which allows attackers to manipulate the SMB protocol communication between virtual machines and host systems. This vulnerability is particularly concerning because it leverages the fundamental virtualization mechanisms that enable Windows Hyper-V to function, making it a core component of the attack surface rather than an isolated issue.
The technical implementation of this vulnerability resides in how Hyper-V processes SMB packets when virtual machines communicate with shared resources on the host system. When a virtual machine attempts to access SMB shares through the vSMB implementation, the system fails to properly validate the packet structures and data integrity checks that should occur during this communication process. This validation failure creates opportunities for attackers to craft malicious SMB packets that can bypass normal access controls and privilege boundaries. The vulnerability operates at the hypervisor level where virtual machines interact with shared storage resources, making it particularly dangerous as it can be exploited to gain unauthorized access to system resources, manipulate virtual machine configurations, and potentially compromise the entire host system. According to CWE classification, this vulnerability maps to CWE-129, which addresses improper validation of input boundaries, and CWE-264, covering permissions, privileges, and access controls.
The operational impact of this vulnerability extends far beyond simple privilege escalation, as it fundamentally undermines the security model of virtualized environments. Attackers can exploit this weakness to gain SYSTEM-level privileges on affected systems, potentially leading to complete system compromise and unauthorized access to sensitive data. The vulnerability is particularly dangerous in enterprise environments where Hyper-V is extensively used for virtualization, as it could allow attackers to move laterally within networks and access multiple virtual machines simultaneously. The attack requires minimal privileges initially, making it accessible to attackers who may have only basic user access to a system. This characteristic aligns with ATT&CK technique T1068, which covers 'Exploitation for Privilege Escalation', and T1059, covering 'Command and Scripting Interpreter', as attackers can leverage the elevated privileges to execute additional malicious activities. Organizations running affected Windows versions are at risk of data breaches, system compromise, and potential lateral movement attacks that could affect entire virtualized infrastructures.
Mitigation strategies for this vulnerability require immediate patch deployment through Microsoft's regular security updates, as the primary fix involves proper validation of vSMB packet data within the Hyper-V implementation. System administrators should prioritize updating affected systems to the latest Windows 10 and Windows Server 2016 versions that contain the security patches. Additionally, network segmentation and access control measures can help limit the potential impact of exploitation by restricting virtual machine access to sensitive resources. Organizations should also implement monitoring solutions that can detect anomalous SMB traffic patterns that might indicate exploitation attempts. The vulnerability highlights the importance of maintaining up-to-date virtualization security measures and implementing defense-in-depth strategies that protect both physical and virtual environments. Security teams should conduct vulnerability assessments to identify systems running affected Hyper-V configurations and ensure proper patch management protocols are in place to prevent similar vulnerabilities from being exploited in the future.