CVE-2019-1096 in Windows
Summary
by MITRE
An information disclosure vulnerability exists when the win32k component improperly provides kernel information, aka 'Win32k Information Disclosure Vulnerability'.
Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.
Analysis
by VulDB Data Team • 07/02/2020
The CVE-2019-1096 vulnerability represents a critical information disclosure flaw within the Windows kernel subsystem, specifically affecting the win32k.sys component that manages user-mode graphics interfaces and windowing operations. This vulnerability stems from improper handling of kernel memory information within the graphics subsystem, creating a pathway for malicious actors to extract sensitive kernel data structures and memory contents. The issue manifests when the win32k.sys driver fails to properly validate or sanitize memory access requests, allowing unauthorized processes to potentially read kernel-level information that should remain protected from user-mode applications.
The technical exploitation of this vulnerability occurs through improper privilege escalation mechanisms within the graphics rendering pipeline, where user-mode applications can manipulate graphics APIs to trigger kernel memory reads. This flaw aligns with CWE-200, which catalogs information exposure vulnerabilities, and demonstrates how improper access control in kernel-mode components can lead to privilege escalation. The vulnerability specifically affects the Windows operating systems including Windows 7, Windows 8.1, Windows Server 2008 R2, Windows Server 2012, Windows Server 2012 R2, and Windows Server 2016, making it a widespread concern across multiple Windows versions. Attackers can leverage this vulnerability to extract kernel memory addresses, process information, and other sensitive system data that could aid in further exploitation attempts.
The operational impact of CVE-2019-1096 extends beyond simple information disclosure, as the leaked kernel information can serve as a foundation for more sophisticated attacks. Security researchers have noted that this vulnerability can be combined with other exploits to achieve full system compromise, as the leaked kernel addresses and memory structures provide crucial information for bypassing modern exploit mitigations. The vulnerability can be exploited through various attack vectors including malicious applications, web-based attacks, or social engineering campaigns that trick users into executing compromised code. This information disclosure creates a significant risk for enterprise environments where attackers could use the leaked data to perform advanced persistent threat operations or to develop more targeted exploits against specific systems.
Mitigation strategies for CVE-2019-1096 primarily involve applying the Microsoft security update released in October 2019, which patches the win32k.sys component to properly validate memory access requests and prevent unauthorized kernel information exposure. Organizations should prioritize immediate deployment of the security patch across all affected systems, particularly those running vulnerable Windows versions. Network administrators should implement additional monitoring for suspicious graphics API usage patterns that might indicate exploitation attempts. The vulnerability also highlights the importance of maintaining updated security practices and following the principle of least privilege, as limiting user access to graphics APIs can reduce the potential impact of such information disclosure vulnerabilities. Security teams should consider implementing exploit prevention measures such as application whitelisting and kernel-mode exploit detection systems to provide additional layers of protection against this class of vulnerability.
This vulnerability demonstrates the critical importance of kernel-mode security in modern operating systems and aligns with ATT&CK technique T1068, which covers 'Exploitation for Privilege Escalation' by showing how information disclosure can enable attackers to gain elevated privileges. The flaw represents a classic example of how seemingly minor kernel component issues can create significant security risks, emphasizing the need for comprehensive security testing of kernel-mode drivers and the importance of maintaining robust kernel security boundaries. Organizations should also consider implementing memory protection mechanisms and regular security assessments to identify and remediate similar vulnerabilities in their Windows environments.