CVE-2011-0665 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-2011-0665 vulnerability represents a critical use-after-free condition in the win32k.sys kernel-mode driver component of Microsoft Windows operating systems. This vulnerability exists within the graphics subsystem's kernel driver that manages user interface elements and windowing operations, making it particularly dangerous as it can be exploited by local attackers to escalate privileges from standard user level to SYSTEM level access. The flaw specifically manifests in how the driver handles object references and memory management during window and graphics object operations, creating a scenario where freed memory can be accessed and manipulated by malicious code.
The technical implementation of this vulnerability stems from improper handling of driver object management within the win32k.sys module, which is responsible for processing graphics and user interface operations in Windows kernel space. When a crafted application attempts to manipulate graphics objects through the Windows API, it can cause the kernel driver to free memory associated with a graphics object while still maintaining references to that memory location. This creates a window where malicious code can overwrite the freed memory with malicious payloads, leading to arbitrary code execution with kernel-level privileges. The vulnerability is classified under CWE-416 as a Use After Free condition, which is a common and dangerous class of memory safety issues in kernel-mode drivers where freed memory is accessed after deallocation.
The operational impact of this vulnerability is severe and far-reaching across multiple Windows versions including 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. Attackers can leverage this vulnerability to execute code with the highest privileges available in the system, potentially leading to complete system compromise. The local privilege escalation aspect means that an attacker does not require network access or complex exploitation techniques, making this vulnerability particularly dangerous in environments where local access is possible. This vulnerability aligns with ATT&CK technique T1068 which describes the use of local privilege escalation techniques, and specifically targets the privilege escalation tactic by exploiting kernel-mode driver flaws.
Mitigation strategies for CVE-2011-0665 primarily involve applying the Microsoft security update released as part of MS11-034, which addresses the specific use-after-free condition in win32k.sys. System administrators should ensure all affected Windows systems receive the patch immediately, as this vulnerability was actively exploited in the wild. Additionally, implementing security measures such as disabling unnecessary graphics functionality, employing kernel-mode driver signature enforcement, and monitoring for suspicious kernel-mode activity can help reduce the attack surface. The vulnerability demonstrates the importance of proper memory management in kernel-mode drivers and highlights the need for comprehensive security testing of system components that handle user input and graphics operations. Organizations should also consider implementing the principle of least privilege and maintaining up-to-date security patches to protect against similar vulnerabilities in the future.