CVE-2011-1875 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 CVEs listed in MS11-054, aka "Win32k Use After Free Vulnerability."
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Analysis
by VulDB Data Team • 11/14/2021
The CVE-2011-1875 vulnerability represents a critical use-after-free flaw 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 responsible for managing user interface elements and windowing operations, making it a prime target for privilege escalation attacks. The vulnerability stems from improper handling of driver object management where freed memory locations are accessed after being deallocated, creating a predictable exploitation vector for malicious code.
The technical exploitation of this vulnerability occurs through a crafted application that manipulates the win32k.sys driver's object management routines. When a vulnerable system processes certain user interface operations, the kernel-mode driver fails to properly validate object references, leading to a scenario where memory that has been freed but not properly cleared can still be accessed by subsequent operations. This creates a race condition where an attacker can manipulate the system to cause the driver to reference freed memory locations, potentially allowing code execution with kernel-level privileges. The vulnerability is classified as a CWE-416 Use After Free, which specifically addresses the improper use of memory after it has been freed by the system. This weakness enables attackers to potentially execute arbitrary code with the highest privileges available, making it particularly dangerous for system compromise.
The operational impact of CVE-2011-1875 extends beyond simple privilege escalation to encompass full system compromise capabilities. Local attackers who can execute code on a vulnerable system can leverage this vulnerability to gain kernel-level privileges, effectively bypassing all user-mode security controls and access restrictions. The attack vector requires local system access, but once successful, the attacker gains complete control over the target system, including the ability to install malware, modify system files, and access all user data. This vulnerability was particularly significant because it affected multiple versions of Windows, creating a widespread attack surface that made it attractive to malware authors and nation-state actors. The vulnerability's classification under ATT&CK technique T1068, 'Exploitation for Privilege Escalation', demonstrates its role in enabling attackers to move from user-level access to system-level control.
Mitigation strategies for CVE-2011-1875 focus primarily on timely patch deployment and system hardening measures. Microsoft released security update MS11-054 to address this vulnerability, which should be applied immediately to all affected systems. Organizations should implement robust patch management processes to ensure all vulnerable systems receive updates promptly. Additional defensive measures include disabling unnecessary user interface components, implementing application whitelisting policies, and monitoring for suspicious process activity that might indicate exploitation attempts. System administrators should also consider implementing runtime protection mechanisms such as Data Execution Prevention and Address Space Layout Randomization to make exploitation more difficult. The vulnerability highlights the importance of maintaining up-to-date security patches and demonstrates how kernel-mode vulnerabilities can provide attackers with the most powerful attack vectors available, emphasizing the critical need for continuous security monitoring and proactive vulnerability management.