CVE-2011-0667 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 SP1 and SP2, Windows Server 2008 Gold, SP2, R2, and R2 SP1, and Windows 7 Gold and SP1 allows local users to gain privileges via a crafted application that leverages incorrect driver object management, a different vulnerability than other "Vulnerability Type 1" CVEs listed in MS11-034, aka "Win32k Use After Free Vulnerability."
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Analysis
by VulDB Data Team • 11/02/2021
The CVE-2011-0667 vulnerability represents a critical use-after-free condition in the win32k.sys kernel-mode driver component of Microsoft Windows operating systems. This vulnerability specifically affects Windows XP SP2 and SP3, Windows Server 2003 SP2, Windows Vista SP1 and SP2, Windows Server 2008 Gold, SP2, R2, and R2 SP1, as well as Windows 7 Gold and SP1. The flaw resides in the kernel-mode driver object management mechanisms that handle user interface components, making it particularly dangerous as it operates at the core level of the operating system. The vulnerability is classified under CWE-416 as a Use After Free condition, which occurs when a program continues to reference memory after it has been freed, leading to unpredictable behavior and potential exploitation. This particular vulnerability is distinct from other "Vulnerability Type 1" issues referenced in MS11-034, indicating it operates through different attack vectors and exploitation techniques.
The technical exploitation of this vulnerability occurs when a malicious application manipulates the win32k.sys driver through improper management of driver objects, specifically targeting the kernel-mode components responsible for windowing system functionality. When the driver processes certain user interface operations, it fails to properly validate or manage memory references, creating a window where freed memory can be accessed and potentially overwritten by malicious code. This flaw allows local attackers with standard user privileges to escalate their access to kernel-level privileges, effectively bypassing the operating system's security boundaries. The exploitation process typically involves crafting a malicious application that triggers the vulnerable code path in win32k.sys, causing the driver to free memory that is subsequently accessed by the attacker's code, enabling privilege escalation attacks.
The operational impact of CVE-2011-0667 extends beyond simple privilege escalation, as it represents a fundamental breakdown in the kernel-mode security model of affected Windows versions. Attackers who successfully exploit this vulnerability can gain complete control over affected systems, potentially leading to data theft, system compromise, and lateral movement within network environments. The vulnerability's presence in multiple Windows versions from XP through Windows 7 means that organizations with legacy systems face significant risk, particularly in enterprise environments where older operating systems may still be in use. This vulnerability directly maps to ATT&CK technique T1068, which covers "Exploitation for Privilege Escalation," and T1059, covering "Command and Scripting Interpreter," as exploitation typically involves running malicious code within the kernel context. The attack surface is particularly concerning as it requires minimal user interaction beyond executing the malicious application, making it suitable for automated exploitation in targeted attacks.
Organizations should prioritize immediate patching of systems affected by CVE-2011-0667, as Microsoft released security update MS11-034 to address this vulnerability. The patch implements proper memory management controls within win32k.sys to prevent the use-after-free condition from occurring during driver object operations. Additionally, system administrators should implement defensive measures such as disabling unnecessary user interface components, applying the principle of least privilege, and monitoring for suspicious process activities that might indicate exploitation attempts. Security teams should also consider implementing runtime protections and behavioral monitoring to detect anomalous kernel-mode activities that could indicate exploitation of this vulnerability. The vulnerability serves as a reminder of the critical importance of maintaining up-to-date security patches and the risks associated with running unsupported operating systems, as Windows XP and Server 2003 reached end-of-life and no longer receive security updates, leaving systems vulnerable to such exploits.