CVE-2011-1241 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-2011-1241 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 manifests in the improper management of driver objects within the kernel-mode environment, creating a condition where memory that has been freed is still accessed by subsequent operations. This particular vulnerability is distinct from other "Vulnerability Type 1" CVEs referenced in MS11-034, establishing it as a separate and significant security concern within the Windows kernel architecture.
The technical exploitation of this vulnerability occurs when a malicious application manipulates the win32k.sys driver through improper object management techniques that lead to a use-after-free condition. When a kernel-mode driver object is freed from memory but references to it persist, an attacker can potentially manipulate the freed memory location to execute arbitrary code with kernel-level privileges. The vulnerability stems from inadequate validation of driver object states and improper memory management practices within the win32k.sys component, which handles user interface kernel-mode operations. This flaw enables local privilege escalation attacks where a user with standard privileges can elevate their access level to system-level privileges, effectively compromising the entire operating system. The vulnerability falls under CWE-416, which specifically addresses Use After Free conditions in software development.
The operational impact of CVE-2011-1241 is severe and far-reaching across the affected Windows platforms, as it provides a pathway for local attackers to achieve privilege escalation without requiring remote network access. This makes the vulnerability particularly dangerous in environments where users may have legitimate access to systems but lack administrative privileges. The exploitation of this vulnerability can result in complete system compromise, allowing attackers to execute arbitrary code, modify system files, install malware, and potentially establish persistent backdoors. The attack surface is broad due to the widespread deployment of affected Windows versions, making this vulnerability a prime target for malware authors and advanced persistent threat groups. Security researchers have noted that this vulnerability can be leveraged in conjunction with other exploits to create more sophisticated attack chains, demonstrating its significance within the broader threat landscape.
Mitigation strategies for CVE-2011-1241 primarily focus on applying the official Microsoft security patches released as part of MS11-034, which specifically address the win32k.sys use-after-free vulnerability. Organizations should prioritize immediate patch deployment across all affected systems, particularly those running older Windows versions that may not receive extended support. System administrators should implement additional security measures such as disabling unnecessary user privileges, implementing application whitelisting policies, and monitoring for suspicious kernel-mode activities that might indicate exploitation attempts. The vulnerability's nature aligns with ATT&CK technique T1068, which covers "Exploitation for Privilege Escalation," making it a critical target for defensive security operations. Regular vulnerability assessments and penetration testing should be conducted to identify systems that may not have received the necessary patches, while endpoint detection and response solutions can help detect anomalous behavior patterns associated with this specific vulnerability type.