CVE-2011-1885 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 CVEs listed in MS11-054, aka "Win32k Null Pointer De-reference Vulnerability."
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Analysis
by VulDB Data Team • 11/14/2021
The CVE-2011-1885 vulnerability represents a critical privilege escalation flaw within the Windows kernel-mode driver subsystem, specifically targeting the win32k.sys component that manages graphical user interface elements and windowing operations. This vulnerability exists in multiple Windows operating systems including 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, making it one of the most widely affected vulnerabilities of its type. The flaw manifests when a malicious application triggers a NULL pointer dereference condition within the win32k.sys driver, which operates at kernel level and handles critical graphical operations such as window management, input processing, and GDI (Graphics Device Interface) functions. This vulnerability is classified under CWE-476 as a NULL pointer dereference, which represents a fundamental programming error where software attempts to access memory at a NULL address, leading to system instability and potential privilege escalation. The vulnerability operates at the kernel level, meaning that any successful exploitation can result in complete system compromise, as the attacker gains the same privileges as the kernel itself, effectively bypassing all user-mode security boundaries.
The operational impact of this vulnerability is severe and far-reaching, as it enables local users to escalate their privileges from standard user level to SYSTEM level without requiring any special authentication or administrative credentials. The attack vector requires only a locally running malicious application that can manipulate the win32k.sys driver through carefully crafted graphical operations or windowing functions that trigger the NULL pointer dereference. This type of vulnerability is particularly dangerous because it can be exploited by malware that is already present on a system, such as through social engineering attacks, drive-by downloads, or other initial compromise vectors. The vulnerability's classification under the ATT&CK framework places it within the Privilege Escalation category, specifically targeting the 'Windows Privilege Escalation' technique where adversaries leverage software flaws to gain elevated access rights. The fact that this vulnerability affects multiple Windows versions simultaneously creates a significant challenge for system administrators and security teams, as it requires coordinated patching across diverse environments and operating system versions.
Mitigation strategies for CVE-2011-1885 focus primarily on applying the official Microsoft security patches released as part of MS11-054, which addressed this specific vulnerability along with related issues. Organizations should prioritize immediate patch deployment across all affected systems, particularly those running older Windows versions such as XP and Server 2003, which are more susceptible to exploitation due to their limited security features and extended support lifecycle. System administrators should implement additional security measures including disabling unnecessary graphical services, implementing application whitelisting policies, and monitoring for suspicious process behaviors that might indicate exploitation attempts. The vulnerability's nature as a kernel-mode flaw means that traditional user-mode security controls such as antivirus software may not be sufficient to prevent exploitation, as the attack operates below the level of typical security monitoring. Network segmentation and least privilege principles should be enforced to limit the potential impact of successful exploitation, while regular security assessments and vulnerability scanning should be conducted to identify unpatched systems. Organizations should also consider implementing behavioral monitoring solutions that can detect anomalous graphical operations or privilege escalation attempts that might indicate exploitation of this vulnerability. The remediation process must be carefully planned and tested, as kernel-level patches can sometimes introduce compatibility issues with legacy applications or hardware drivers that rely on the vulnerable functionality.