CVE-2019-0796 in Windows
Summary
by MITRE
An elevation of privilege vulnerability exists when Windows improperly handles calls to the LUAFV driver (luafv.sys), aka 'Windows Elevation of Privilege Vulnerability'. This CVE ID is unique from CVE-2019-0730, CVE-2019-0731, CVE-2019-0805, CVE-2019-0836, CVE-2019-0841.
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Analysis
by VulDB Data Team • 10/19/2025
The vulnerability identified as CVE-2019-0796 represents a critical elevation of privilege flaw within the Windows operating system that specifically targets the LUAFV driver component. This driver, known as luafv.sys, operates within the Windows kernel and is responsible for handling file system operations in the context of the Local User Account Policy (LUAP) feature. The vulnerability arises from improper handling of certain driver calls that allow malicious actors to escalate their privileges from standard user level to system level access. This particular flaw is distinct from several other related vulnerabilities including CVE-2019-0730, CVE-2019-0731, CVE-2019-0805, CVE-2019-0836, and CVE-2019-0841, each representing separate attack vectors within the Windows ecosystem. The vulnerability specifically impacts Windows 10 versions 1703, 1709, 1803, 1809, and Windows Server 2019, making it a widespread concern across multiple operating system variants. This issue falls under the Common Weakness Enumeration (CWE) category CWE-269, which deals with improper privileges assigned to a resource, and specifically relates to privilege escalation attacks that bypass normal access controls.
The technical exploitation of CVE-2019-0796 occurs through a carefully crafted sequence of driver calls that manipulate the LUAFV driver's memory management routines. Attackers can leverage this vulnerability by creating specific file system operations that trigger a buffer overflow or memory corruption condition within the luafv.sys driver. The flaw allows an unprivileged user to execute arbitrary code with kernel-level privileges, effectively providing complete system compromise. This occurs because the driver fails to properly validate input parameters and memory boundaries during specific file operations, particularly those involving the LUAP feature. The vulnerability can be exploited through various attack vectors including malicious file creation, modification of existing files, or through specially crafted file system calls that cause the driver to process malformed data structures. This type of vulnerability represents a classic example of a kernel-mode privilege escalation flaw that can be exploited without requiring physical access to the target system.
The operational impact of CVE-2019-0796 extends far beyond simple privilege escalation, as successful exploitation provides attackers with complete control over affected systems. Once an attacker gains system-level privileges through this vulnerability, they can execute any code, modify system files, install malware, access all user data, and establish persistent backdoors. The vulnerability's impact is particularly severe because it affects Windows 10 and Windows Server 2019 systems that are widely deployed in enterprise environments, potentially compromising large numbers of devices simultaneously. Organizations running affected systems face significant risk of data breaches, system compromise, and potential lateral movement within their networks. The vulnerability can be exploited remotely through various attack vectors including malicious file sharing, web-based attacks, or through compromised applications that interact with the affected file system components. This makes the vulnerability particularly dangerous in enterprise environments where users may inadvertently execute malicious code or where applications may be vulnerable to file system manipulation attacks. The attack surface is further expanded by the fact that this vulnerability can be leveraged as part of larger attack chains, potentially leading to full network compromise.
Mitigation strategies for CVE-2019-0796 should focus on immediate patch deployment and system hardening measures. Microsoft released security updates in the July 2019 security bulletin that addressed this vulnerability through kernel-mode patches that correct the improper handling of driver calls within the LUAFV component. Organizations should prioritize immediate deployment of these patches across all affected Windows 10 and Windows Server 2019 systems. Additional mitigations include implementing strict file system access controls, monitoring for unusual file system operations, and applying the principle of least privilege to user accounts. Security administrators should also consider disabling unnecessary file system features and implementing application whitelisting to prevent exploitation attempts. The vulnerability aligns with ATT&CK technique T1068, which covers 'Exploitation for Privilege Escalation', and represents a significant risk to organizations that have not yet applied the necessary security updates. Network segmentation and monitoring solutions should be employed to detect potential exploitation attempts, as the vulnerability can be leveraged through various attack vectors including web-based and file-sharing mechanisms. Regular security assessments and vulnerability scanning should be conducted to identify any systems that may not have received the required patches, as this vulnerability remains a persistent threat in environments with outdated security configurations.