CVE-2017-0186 in Hyper-V
Summary
by MITRE
A denial of service vulnerability exists when Microsoft Hyper-V Network Switch running on a Windows 10, Windows 8.1, Windows Server 2012, Windows Server 2012 R2, or Windows Server 2016 host server fails to properly validate input from a privileged user on a guest operating system, aka "Hyper-V Denial of Service Vulnerability." This CVE ID is unique from CVE-2017-0178, CVE-2017-0179, CVE-2017-0182, CVE-2017-0183, CVE-2017-0184, and CVE-2017-0185.
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Analysis
by VulDB Data Team • 12/23/2024
The CVE-2017-0186 vulnerability represents a critical denial of service flaw within Microsoft Hyper-V Network Switch functionality, specifically affecting virtualized environments running on Windows 10, Windows 8.1, Windows Server 2012, Windows Server 2012 R2, and Windows Server 2016 platforms. This vulnerability stems from inadequate input validation mechanisms within the Hyper-V hypervisor's network switching component, which operates at the kernel level of the host operating system. The flaw specifically manifests when a privileged user executing within a guest operating system can manipulate input parameters that are not properly sanitized or validated by the host's Hyper-V Network Switch module. This issue falls under the CWE-20 category of "Improper Input Validation" and represents a classic example of privilege escalation leading to system instability, as the vulnerability leverages the trust relationship between guest and host systems within virtualized environments.
The technical exploitation of this vulnerability occurs through malicious input manipulation within the virtual network switch configuration, where a compromised guest operating system user with elevated privileges can craft specific network packets or configuration parameters that bypass validation checks implemented by the Hyper-V host. The network switch component, which handles virtual network traffic between virtual machines and physical network interfaces, fails to properly validate incoming data structures or control information that originates from guest operating systems. This allows the malicious input to potentially corrupt internal data structures or trigger unexpected behavior within the hypervisor's memory management or network processing routines. The vulnerability demonstrates the inherent risk of insufficient sandboxing between virtualized environments and the host system, particularly when dealing with network-related components that require direct hardware access or privileged operations.
The operational impact of CVE-2017-0186 extends beyond simple service disruption, as it can lead to complete system instability and potential denial of service across all virtual machines hosted on the affected system. When successfully exploited, the vulnerability can cause the Hyper-V Network Switch to crash or become unresponsive, resulting in network connectivity loss for all virtual machines utilizing that particular network switch configuration. This creates cascading effects throughout virtualized environments, potentially affecting critical business applications and services that depend on stable virtual machine operations. The vulnerability is particularly concerning in enterprise environments where multiple virtual machines share common network switches, as a single compromised guest system could potentially affect the entire virtual infrastructure. The flaw aligns with ATT&CK technique T1068, "Exploitation for Privilege Escalation," and T1499, "Endpoint Denial of Service," as it allows for both privilege escalation within the virtual environment and system-wide service disruption.
Mitigation strategies for CVE-2017-0186 should prioritize immediate patch deployment through Microsoft's regular security updates, as the vulnerability was addressed in the July 2017 security bulletin. Organizations should implement network segmentation and isolation policies to limit the potential impact of compromised guest systems, ensuring that critical virtual machines are not sharing network switches with potentially untrusted or compromised environments. Additionally, monitoring should be implemented to detect unusual network switch behavior or resource consumption patterns that might indicate exploitation attempts. The vulnerability highlights the importance of maintaining strict security boundaries within virtualized environments and underscores the need for comprehensive vulnerability management programs that address both host and guest operating system security. System administrators should also consider implementing additional network monitoring tools and intrusion detection systems specifically designed to detect anomalous behavior in virtualized network environments, as traditional network monitoring may not adequately detect hypervisor-level vulnerabilities that operate below the network protocol stack.