CVE-2011-0677 in Windows
Summary
by MITRE
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 triggers a NULL pointer dereference, a different vulnerability than other "Vulnerability Type 2" CVEs listed in MS11-034, aka "Win32k Null Pointer De-reference Vulnerability."
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Analysis
by VulDB Data Team • 01/18/2025
The vulnerability identified as CVE-2011-0677 represents a critical privilege escalation flaw within the Windows kernel-mode driver component known as win32k.sys. This vulnerability affects multiple versions of Microsoft Windows operating systems including 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 drivers that handle graphical user interface operations, specifically within the win32k.sys module responsible for managing windowing system functionality. This component is fundamental to the Windows operating system's graphical interface and user interaction mechanisms, making it a prime target for exploitation by malicious actors seeking elevated privileges.
The technical nature of this vulnerability stems from a NULL pointer dereference condition that occurs when a crafted application triggers specific conditions within the win32k.sys driver. When the driver encounters a malformed or specially constructed input that leads to a NULL pointer reference, it fails to properly validate the pointer before attempting to access it, resulting in a system crash or potential privilege escalation. This type of vulnerability falls under the Common Weakness Enumeration category CWE-476, which specifically addresses NULL pointer dereference weaknesses in software systems. The flaw is particularly dangerous because it operates at the kernel level where any successful exploitation can result in complete system compromise, allowing local attackers to execute code with the highest privileges available to the system.
The operational impact of CVE-2011-0677 is severe and far-reaching within enterprise environments where Windows systems are prevalent. Local users who can execute malicious code on a vulnerable system can leverage this vulnerability to escalate their privileges from standard user level to SYSTEM level access, effectively granting them complete control over the affected machine. This privilege escalation capability enables attackers to bypass traditional security controls, install malware, modify system files, access sensitive data, and potentially use the compromised system as a launch point for further attacks within a network. The vulnerability's presence in multiple Windows versions means that organizations across different operational environments and security postures were simultaneously at risk, creating widespread exposure that required immediate remediation efforts. The specific nature of the vulnerability as a NULL pointer dereference also makes it particularly challenging to detect and prevent through traditional runtime protections, as the flaw occurs during normal system operation when legitimate graphical interface functions are being executed.
Mitigation strategies for CVE-2011-0677 primarily focus on immediate patch deployment and system hardening measures. Microsoft released a security update as part of MS11-034 that addressed this specific vulnerability, and organizations should prioritize applying this patch across all affected systems. Beyond patching, system administrators should implement additional security controls including user access restrictions, application whitelisting, and enhanced monitoring of system processes that interact with the win32k.sys driver. The vulnerability's classification as a kernel-mode exploit also necessitates consideration of advanced protection mechanisms such as kernel patch protection, driver signature enforcement, and exploit prevention technologies. From an adversarial perspective, this vulnerability aligns with ATT&CK technique T1068 which covers local privilege escalation through kernel exploits, making it a target for both automated exploitation tools and sophisticated threat actors seeking to establish persistent access to compromised systems. Organizations should also conduct thorough vulnerability assessments to identify any systems that may have been compromised before patch deployment, as the exploitation of this vulnerability can occur without user interaction and may leave minimal forensic traces.