CVE-2019-1162 in Windows
Summary
by MITRE
An elevation of privilege vulnerability exists when Windows improperly handles calls to Advanced Local Procedure Call (ALPC). An attacker who successfully exploited this vulnerability could run arbitrary code in the security context of the local system. An attacker could then install programs; view, change, or delete data; or create new accounts with full user rights. To exploit this vulnerability, an attacker would first have to log on to the system. An attacker could then run a specially crafted application that could exploit the vulnerability and take control over an affected system. The update addresses the vulnerability by correcting how Windows handles calls to ALPC.
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Analysis
by VulDB Data Team • 02/21/2026
The vulnerability described in CVE-2019-1162 represents a critical elevation of privilege flaw within the Windows operating system's handling of Advanced Local Procedure Call (ALPC) mechanisms. This weakness resides in the kernel-mode component of Windows that manages inter-process communication through ALPC, which serves as a high-performance communication mechanism for Windows kernel components and user-mode applications. The flaw stems from improper validation of ALPC calls, creating a pathway for malicious code execution with system-level privileges. According to CWE-264, this vulnerability manifests as a weakness in permissions and access control, specifically involving improper handling of security-critical system calls. The vulnerability is particularly dangerous because it allows an attacker to escalate privileges from a standard user account to SYSTEM level, which represents the highest privilege level in Windows security architecture.
The technical exploitation of this vulnerability requires an attacker to first establish a valid user session on the target system, which is a relatively common prerequisite for many local privilege escalation attacks. Once authenticated, the attacker can execute a specially crafted application that leverages the flawed ALPC handling mechanism to gain unauthorized access to system-level resources. The attack vector specifically targets the kernel's processing of ALPC messages, where the system fails to properly validate or sanitize input parameters passed through these communication channels. This allows malicious code to manipulate kernel data structures and execute arbitrary instructions with the highest possible privileges. The vulnerability demonstrates characteristics of a kernel exploit that can be classified under ATT&CK technique T1068, which covers exploit for privilege escalation, specifically targeting local system privileges. The flaw essentially creates a code execution pathway that bypasses normal Windows security boundaries, allowing attackers to circumvent standard access controls and execute malicious payloads with complete system control.
The operational impact of this vulnerability extends far beyond simple privilege escalation, as successful exploitation provides attackers with complete control over the affected system. Once elevated to SYSTEM level, an attacker can install malicious software, modify or delete critical system files, create new user accounts with administrative privileges, and access all data stored on the system. This comprehensive access capability makes the vulnerability particularly attractive to threat actors seeking persistent access to target environments. The vulnerability affects multiple Windows versions including Windows 10, Windows Server 2016, and Windows Server 2019, making it a widespread concern across enterprise environments. The exploitability requirements are relatively straightforward, as it only requires local authentication and the ability to execute code, which can be achieved through various attack vectors including social engineering, drive-by downloads, or compromised legitimate applications. Organizations running affected systems face significant risk of complete system compromise and potential lateral movement within their networks, as the SYSTEM-level access gained through this vulnerability enables attackers to establish persistent backdoors and access sensitive corporate data.
Microsoft addressed this vulnerability through a comprehensive update that corrects the flawed ALPC call handling mechanism in the Windows kernel. The patch ensures proper validation of parameters and message contents when processing ALPC communications, preventing malicious inputs from being processed with elevated privileges. Security researchers have noted that this patch effectively closes the privilege escalation pathway by implementing stricter kernel-mode validation controls that align with the principle of least privilege. Organizations should prioritize deployment of this update across all affected systems, particularly those running server operating systems where the risk of exploitation is higher due to increased attack surface. The mitigation strategy should include regular security assessments to verify patch compliance and monitoring for potential exploitation attempts. Additionally, implementing network segmentation and access control measures can reduce the impact of successful exploitation attempts, while behavioral analytics and endpoint detection solutions can help identify anomalous activities that might indicate exploitation of this vulnerability. The vulnerability serves as a reminder of the critical importance of kernel-level security controls and the potential catastrophic consequences of privilege escalation flaws in operating system components that handle inter-process communications.