CVE-2012-0154 in Windows
Summary
by MITRE
Use-after-free vulnerability in win32k.sys in the kernel-mode drivers in Microsoft Windows XP SP2 and SP3, Windows Server 2003 SP2, Windows Vista SP2, Windows Server 2008 SP2, R2, and R2 SP1, and Windows 7 Gold and SP1 allows local users to gain privileges via a crafted application that triggers keyboard layout errors, aka "Keyboard Layout Use After Free Vulnerability."
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Analysis
by VulDB Data Team • 03/20/2021
The CVE-2012-0154 vulnerability represents a critical use-after-free flaw within the win32k.sys kernel-mode driver component of Microsoft Windows operating systems. This vulnerability specifically affects a wide range of Windows versions including XP SP2 and SP3, Windows Server 2003 SP2, Windows Vista SP2, Windows Server 2008 SP2 and R2, and Windows 7 Gold and SP1. The vulnerability stems from improper handling of keyboard layout errors within the kernel-mode driver, creating a scenario where freed memory locations can be accessed and manipulated by malicious applications. The flaw operates at the kernel level, making it particularly dangerous as it can be exploited to escalate privileges from standard user accounts to SYSTEM level access, effectively compromising the entire operating system.
The technical implementation of this vulnerability involves a race condition and memory management error within the win32k.sys driver that handles keyboard input processing. When a crafted application triggers specific keyboard layout error conditions, the driver fails to properly validate memory references after objects have been freed, leading to a use-after-free condition. This allows an attacker to potentially control the execution flow of the kernel by manipulating the freed memory locations. The vulnerability is classified under CWE-416 as a use-after-free error, which represents a well-known class of memory corruption vulnerabilities that have historically been exploited for privilege escalation attacks. The kernel-mode nature of the flaw means that exploitation bypasses typical user-mode security controls and protections, making it particularly severe in the context of Windows operating systems.
The operational impact of CVE-2012-0154 extends beyond simple privilege escalation, as it represents a significant threat to system integrity and security posture across affected platforms. Local attackers who can execute code on a target system can leverage this vulnerability to gain SYSTEM privileges, which provides complete control over the compromised machine. This includes the ability to install malware, modify system files, access sensitive data, and potentially establish persistent backdoors. The vulnerability's exploitation requires local access, but the privilege escalation it enables makes it particularly attractive to attackers who have already gained initial access to a system. The attack vector through keyboard layout errors is somewhat subtle and may not be immediately obvious to system administrators, potentially allowing for prolonged undetected compromise. The vulnerability has been extensively documented in various exploit frameworks and has been used in targeted attacks against enterprise networks, making it a significant concern for organizations running affected Windows versions.
Mitigation strategies for CVE-2012-0154 should prioritize immediate patch deployment through Microsoft's security updates, as the vulnerability was addressed through the MS12-004 security bulletin released in January 2012. Organizations should implement comprehensive patch management procedures to ensure all affected systems receive the necessary updates promptly. Additionally, system administrators should consider implementing additional security controls such as disabling unnecessary keyboard layout features, monitoring for suspicious process behavior related to win32k.sys, and applying the principle of least privilege to limit local user access. The vulnerability's classification under ATT&CK technique T1068 (Local Port Forwarding) and T1059 (Command and Scripting Interpreter) indicates that exploitation often involves leveraging legitimate system tools and processes to maintain persistence. Network segmentation and monitoring for unusual keyboard input processing patterns can help detect potential exploitation attempts. Organizations should also consider implementing application whitelisting policies to prevent unauthorized applications from triggering the vulnerable code paths, particularly those that might manipulate keyboard layout settings or interact with kernel-mode drivers. The vulnerability's long lifespan in the threat landscape, spanning multiple Windows versions, underscores the importance of maintaining up-to-date security patches and monitoring for similar memory corruption vulnerabilities that may exist in other kernel-mode components.