CVE-2015-2367 in Windows
Summary
by MITRE
win32k.sys in the kernel-mode drivers in Microsoft Windows Server 2003 SP2 and R2 SP2, Windows Vista SP2, Windows Server 2008 SP2 and R2 SP1, Windows 7 SP1, Windows 8, Windows 8.1, Windows Server 2012 Gold and R2, and Windows RT Gold and 8.1 allows local users to obtain sensitive information from uninitialized kernel memory via a crafted application, aka "Win32k Information Disclosure Vulnerability."
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Analysis
by VulDB Data Team • 05/31/2022
The CVE-2015-2367 vulnerability represents a critical information disclosure flaw within the win32k.sys kernel-mode driver component of Microsoft Windows operating systems. This vulnerability affects a broad range of Microsoft products including various versions of Windows Server 2003, Windows Vista, Windows 7, Windows 8, Windows 8.1, and their respective service packs and editions. The flaw resides in the kernel-mode drivers that handle graphical user interface operations, specifically within the win32k.sys module responsible for managing windowing and graphics functions in the Windows kernel. The vulnerability stems from improper initialization of memory structures within the kernel space, creating opportunities for malicious code to access uninitialized memory regions that may contain sensitive data from previous operations or system states.
The technical exploitation of this vulnerability occurs through a crafted application that leverages the kernel-mode driver's insufficient validation of memory access patterns. When the win32k.sys driver processes certain graphical operations, it fails to properly initialize memory buffers before making them available to user-mode applications. This allows local attackers who can execute code on the target system to perform memory reads from uninitialized kernel memory regions, potentially extracting sensitive information such as cryptographic keys, passwords, session tokens, or other confidential data that may have been stored in those memory locations during previous system operations. The vulnerability operates at the kernel level, making it particularly dangerous as it bypasses normal user-mode security boundaries and can access memory that should remain protected.
The operational impact of this vulnerability extends beyond simple information disclosure, as the extracted data could enable more sophisticated attacks including privilege escalation, credential theft, or system compromise. Attackers could potentially use the leaked information to reconstruct cryptographic keys, access session information, or discover other sensitive system data that could be leveraged to further compromise the affected system. The vulnerability is particularly concerning because it affects multiple versions of Windows simultaneously, making it a widespread concern for enterprise environments. The local nature of the attack means that an attacker must already have user-level access to the system, but once achieved, the information disclosure can provide significant advantages for subsequent attack phases, potentially enabling lateral movement or privilege escalation within the compromised environment.
Security professionals should implement multiple layers of mitigation for this vulnerability, beginning with immediate patch management to deploy the Microsoft security updates released to address CVE-2015-2367. Organizations should also consider implementing additional security controls such as kernel-mode driver verification, enhanced monitoring for suspicious memory access patterns, and strict application whitelisting policies to prevent execution of potentially malicious applications. The vulnerability aligns with CWE-1280, which specifically addresses "Improper Initialization of a Resource," and represents a classic example of how kernel-mode memory management flaws can create information disclosure opportunities. From an ATT&CK framework perspective, this vulnerability maps to techniques involving privilege escalation and credential access, as the information disclosure can be leveraged to obtain credentials or cryptographic material. Additionally, the vulnerability demonstrates the importance of proper kernel memory initialization practices and highlights the need for comprehensive security testing of kernel-mode components, particularly those handling graphical user interface operations that interact with both user-mode and kernel-mode processes.