CVE-2019-0712 in Windows
Summary
by MITRE
A denial of service vulnerability exists when Microsoft Hyper-V Network Switch on a host server fails to properly validate input from a privileged user on a guest operating system, aka 'Windows Hyper-V Denial of Service Vulnerability'. This CVE ID is unique from CVE-2019-1309, CVE-2019-1310, CVE-2019-1399.
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Analysis
by VulDB Data Team • 02/11/2024
The vulnerability identified as CVE-2019-0712 represents a critical denial of service weakness within Microsoft Hyper-V Network Switch functionality that specifically impacts host server systems running virtualized environments. This flaw exists in the network switch component that manages virtual network traffic between guest operating systems and the physical network infrastructure, creating a potential attack vector where malicious privileged users within guest VMs can exploit the validation mechanisms to disrupt normal operations. The vulnerability is particularly concerning because it leverages the trust relationship between host and guest systems, allowing an attacker with elevated privileges inside a guest environment to potentially compromise the stability of the entire host infrastructure. The issue stems from insufficient input validation processes within the Hyper-V Network Switch implementation, which fails to properly sanitize or verify data received from trusted guest operating systems that have been granted administrative or privileged access rights.
The technical exploitation of this vulnerability occurs when a privileged user within a guest operating system crafts specific network traffic or configuration inputs that bypass the normal validation checks implemented by the Hyper-V Network Switch. This improper validation allows malicious inputs to be processed without adequate sanitization, potentially causing the network switch component to enter an unstable state or crash entirely. The flaw specifically affects the handling of network packets or configuration parameters that flow from guest VMs to the host's network switch, where the insufficient validation causes the system to fail in processing legitimate network traffic properly. According to CWE classification, this vulnerability maps to CWE-20, which represents "Improper Input Validation," and more specifically relates to CWE-121, "Stack-based Buffer Overflow," and CWE-122, "Heap-based Buffer Overflow," when considering the potential memory corruption scenarios that could result from improper validation handling. The vulnerability demonstrates characteristics consistent with the ATT&CK technique T1499.001, "OS Command Injection," where the improper handling of inputs could lead to execution of unintended commands within the host environment.
The operational impact of CVE-2019-0712 extends beyond simple service disruption to potentially compromise the availability of critical network infrastructure within virtualized environments. When exploited successfully, this vulnerability can cause the Hyper-V Network Switch to become unresponsive or crash entirely, leading to complete loss of network connectivity for all virtual machines hosted on that particular system. This disruption affects not only the specific guest VMs but can also impact other services running on the same host that depend on network connectivity for their operations. The vulnerability's exploitation requires a privileged user within a guest operating system, which means that the attack surface is limited to environments where guest VMs have been granted administrative access rights, but this access is often necessary for legitimate system administration tasks. Organizations running Hyper-V environments with multiple guest VMs face significant risk if proper access controls are not implemented, as a single compromised or malicious guest system could potentially bring down the entire host network infrastructure.
Mitigation strategies for CVE-2019-0712 should focus on both immediate patching and operational security improvements. Microsoft has released security updates that address this vulnerability through patches for affected Hyper-V components, and organizations should prioritize applying these updates to all affected systems. Additionally, implementing network segmentation and access control measures can help limit the potential impact of privilege escalation within guest VMs. Security administrators should consider implementing monitoring solutions that can detect unusual network traffic patterns or configuration changes that might indicate exploitation attempts. The vulnerability highlights the importance of least privilege principles in virtualized environments, where guest VMs should be granted only the minimum necessary privileges to perform their required functions. Organizations should also consider implementing network isolation between critical systems and those running untrusted or potentially compromised guest VMs, and regular security assessments of virtualized environments should include evaluation of the Hyper-V Network Switch configurations and their vulnerability to input validation issues. The remediation process should include verification that all Hyper-V hosts have been properly updated and that network switch configurations are properly hardened against potential exploitation attempts.