CVE-2011-1228 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 CVE-2011-1228 vulnerability represents a critical privilege escalation flaw within the Windows kernel-mode driver subsystem, specifically targeting the win32k.sys component that manages user interface elements and graphics rendering. This vulnerability exists in multiple Windows operating systems 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 manifests when a malicious application triggers a null pointer dereference condition within the win32k.sys driver, allowing local attackers to escalate their privileges from standard user level to system level access. This vulnerability is categorized under CWE-476 as a null pointer dereference, which represents a fundamental programming error where the system attempts to access memory through a pointer that has not been properly initialized to a valid memory address. The technical implementation involves the kernel-mode driver failing to properly validate input parameters during user interface processing operations, creating a path where untrusted input can cause the driver to attempt to access memory at address zero, resulting in a system crash or privilege escalation.
The operational impact of this vulnerability is severe as it enables local privilege escalation attacks that can be exploited by any user with access to the system, regardless of their initial security context. Attackers can craft malicious applications that manipulate the win32k.sys driver through legitimate user interface functions, exploiting the underlying null pointer dereference to execute arbitrary code with kernel-level privileges. This represents a significant threat vector because the vulnerability operates within the kernel-mode driver space where all system operations are processed with the highest privileges, making it particularly dangerous for enterprise environments where user accounts may have elevated privileges or where attackers can leverage other initial access vectors to reach this privilege escalation stage. The vulnerability differs from other "Vulnerability Type 2" CVEs referenced in MS11-034, indicating it represents a distinct exploitation pathway that requires different defensive measures. From an att&ck framework perspective, this vulnerability maps to privilege escalation techniques and specifically relates to the T1068 privilege escalation tactic, where adversaries leverage system-level vulnerabilities to gain elevated access. The vulnerability can be exploited through various attack chains including social engineering to convince users to run malicious applications, or through automated exploitation tools that can be deployed on compromised systems.
Mitigation strategies for CVE-2011-1228 focus on both immediate patching and operational security measures. Microsoft released security update MS11-034 that addresses this vulnerability by implementing proper null pointer validation within the win32k.sys driver. Organizations should prioritize immediate deployment of this patch across all affected systems, particularly in enterprise environments where the attack surface is larger and the potential impact more significant. Additionally, system hardening measures should include implementing application whitelisting policies to prevent unauthorized applications from executing, reducing the attack surface for exploitation. Network segmentation and least privilege access controls can help limit the potential impact of successful exploitation attempts, while monitoring systems should be configured to detect unusual privilege escalation activities or kernel-mode driver behavior that might indicate exploitation attempts. The vulnerability highlights the importance of proper input validation in kernel-mode code and demonstrates how seemingly minor programming errors in system-critical components can result in severe security implications. Security professionals should also consider implementing behavioral monitoring for unusual driver behavior and ensure regular vulnerability assessments are conducted to identify similar issues in other kernel-mode components. This vulnerability serves as a reminder of the critical importance of secure coding practices in system-level software development and the potential consequences of insufficient validation of input parameters in privileged execution contexts.