CVE-2018-0961 in Windows
Summary
by MITRE
A remote code execution vulnerability exists when Windows Hyper-V on a host server fails to properly validate vSMB packet data, aka "Hyper-V vSMB Remote Code Execution Vulnerability." This affects Windows Server 2016, Windows 10, Windows 10 Servers.
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Analysis
by VulDB Data Team • 03/08/2023
The CVE-2018-0961 vulnerability represents a critical remote code execution flaw within Microsoft Windows Hyper-V virtualization infrastructure, specifically affecting vSMB (virtual SMB) packet validation mechanisms. This vulnerability resides in the Hyper-V virtualization layer's handling of Server Message Block protocol communications between host and guest virtual machines, creating a pathway for malicious actors to execute arbitrary code on affected systems. The flaw manifests when the Hyper-V host server fails to properly validate incoming vSMB packet data structures, allowing attackers to craft specially malformed packets that can bypass normal security boundaries.
The technical root cause of this vulnerability stems from insufficient input validation within the Hyper-V vSMB implementation, which operates as part of the Windows kernel's virtualization subsystem. When a guest virtual machine attempts to communicate with the host through vSMB operations, the host server processes these packets without adequate sanitization of the data fields. This validation gap enables attackers to inject malicious data sequences that can trigger buffer overflows, memory corruption, or other exploitable conditions within the Hyper-V kernel components. The vulnerability specifically impacts systems running Windows Server 2016, Windows 10, and Windows 10 Server editions, where Hyper-V virtualization features are enabled and actively utilized.
From an operational perspective, this vulnerability presents a severe risk to enterprise environments that rely on Hyper-V virtualization, as it allows remote attackers to achieve code execution privileges on the host system without requiring authentication. Successful exploitation can result in complete compromise of the virtualization host, potentially enabling attackers to escape from guest virtual machines and gain access to the underlying physical infrastructure. The impact extends beyond individual systems to affect entire virtualized environments, as compromised hosts can serve as launching points for further attacks against other virtual machines or network resources. This vulnerability aligns with attack patterns documented in the MITRE ATT&CK framework under the 'Execution' and 'Lateral Movement' phases, particularly targeting the 'Virtualization and Container Escape' techniques.
The security implications of CVE-2018-0961 are amplified by the widespread adoption of Hyper-V virtualization across enterprise environments and the potential for privilege escalation that could occur through successful exploitation. Organizations utilizing Windows Server 2016, Windows 10, and Windows 10 Server platforms with Hyper-V enabled must consider immediate remediation measures to protect against this vulnerability. The flaw represents a significant concern for cloud service providers, data centers, and any organization maintaining virtualized infrastructure where guest-to-host communication occurs through vSMB protocols. Mitigation strategies should include applying Microsoft security patches promptly, implementing network segmentation to limit vSMB traffic, and monitoring for anomalous packet patterns that may indicate exploitation attempts. This vulnerability demonstrates the critical importance of proper input validation in kernel-level components and aligns with CWE-129, which addresses insufficient validation of length of inputs, as well as CWE-119, which covers weak buffer access protections in memory management functions.