CVE-2011-0662 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 • 03/19/2021
The CVE-2011-0662 vulnerability represents a critical use-after-free flaw in the win32k.sys kernel-mode driver component of Microsoft Windows operating systems. This vulnerability affects a broad range of Windows versions including Windows xp sp2 and sp3, windows server 2003 sp2, windows vista sp1 and sp2, windows server 2008 gold and sp2, windows server 2008 r2 and r2 sp1, and windows 7 gold and sp1. The flaw resides in the kernel-mode driver management system where improper handling of driver objects creates conditions that allow malicious code to exploit memory access patterns. According to the ms11-034 vulnerability classification, this represents a distinct vulnerability type from other "vulnerability type 1" issues, indicating the complexity and unique nature of the memory management flaw. The vulnerability specifically targets the win32k.sys driver which is responsible for managing user-mode graphics and windowing components in the windows kernel, making it a prime target for privilege escalation attacks.
The technical exploitation of this vulnerability occurs when a crafted application manipulates the kernel-mode driver object management system in such a way that memory allocated to a driver object is freed but subsequently accessed by malicious code. This use-after-free condition creates a scenario where an attacker can control the memory layout and potentially execute arbitrary code with kernel-level privileges. The flaw demonstrates poor memory management practices within the win32k.sys driver where the system fails to properly validate object references before allowing access to freed memory regions. The vulnerability is particularly dangerous because it operates at the kernel level, bypassing standard user-mode security controls and allowing local users to escalate their privileges to SYSTEM level access. This type of vulnerability falls under the common weakness enumeration category of cwe-416 use after free, which specifically addresses improper handling of memory that has been freed but still referenced.
The operational impact of this vulnerability extends beyond simple privilege escalation as it provides attackers with complete system compromise capabilities. Once exploited, the vulnerability allows local users to execute code with the highest possible privileges, effectively granting them complete control over the affected system. Attackers can leverage this vulnerability to install backdoors, modify system files, steal sensitive data, or establish persistent access to compromised systems. The widespread affected versions mean that organizations running any of the listed windows operating systems remain vulnerable to exploitation. The vulnerability's presence in multiple windows versions including server operating systems makes it particularly concerning for enterprise environments where these systems are commonly deployed. Security researchers have noted that the exploitation of this vulnerability often requires sophisticated techniques due to modern exploit mitigation mechanisms like address space layout randomization and data execution prevention, though these protections can be bypassed through advanced exploitation methods.
Mitigation strategies for CVE-2011-0662 should focus on immediate patching and system hardening measures. Microsoft released security update ms11-034 to address this vulnerability, and organizations should prioritize applying this patch across all affected systems. Additionally, implementing defense-in-depth strategies such as disabling unnecessary services, applying strict access controls, and monitoring for suspicious system behavior can help reduce the attack surface. System administrators should also consider implementing application whitelisting policies to prevent unauthorized applications from running and exploiting the vulnerability. The vulnerability's classification as a kernel-mode exploit means that traditional endpoint protection solutions may not provide adequate protection, requiring more sophisticated monitoring and detection capabilities. Organizations should also review their patch management processes to ensure timely deployment of security updates and maintain up-to-date vulnerability assessments to identify systems that may still be running affected versions of windows operating systems. According to the mitre attack framework, this vulnerability would be classified as a privilege escalation technique leveraging kernel-mode exploitation, placing it in the context of advanced persistent threat campaigns where attackers seek to establish persistent access to target systems.