CVE-2016-3250 in Windows
Summary
by MITRE
The kernel-mode drivers in Microsoft Windows Server 2012 and Windows 10 Gold and 1511 allow local users to gain privileges via a crafted application, aka "Win32k Elevation of Privilege Vulnerability."
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Analysis
by VulDB Data Team • 09/01/2022
The vulnerability identified as CVE-2016-3250 represents a critical privilege escalation flaw within the kernel-mode drivers of Microsoft Windows operating systems, specifically affecting Windows Server 2012 and Windows 10 versions Gold and 1511. This vulnerability resides in the win32k.sys driver component which manages user interface elements and graphics rendering functions within the Windows kernel. The flaw enables local attackers with standard user privileges to execute malicious code that can elevate their security context to system level, effectively bypassing the operating system's security model and gaining complete control over the affected system.
The technical root cause of this vulnerability stems from improper validation of user-supplied data within the win32k.sys driver, which processes windowing and graphics-related operations. When a malicious application interacts with the graphics subsystem through legitimate Win32 API calls, the driver fails to properly validate input parameters, allowing attackers to manipulate memory structures and execute arbitrary code with kernel-level privileges. This type of vulnerability falls under the Common Weakness Enumeration category CWE-121, which describes stack-based buffer overflow conditions where insufficient bounds checking allows attackers to overwrite memory locations. The vulnerability specifically manifests when the driver processes certain graphics-related function calls that do not properly validate the size or content of user-provided parameters, creating a pathway for attackers to manipulate the kernel's execution flow.
The operational impact of CVE-2016-3250 is severe and far-reaching within enterprise environments where Windows systems are prevalent. Local attackers who successfully exploit this vulnerability can achieve system-level compromise without requiring any special authentication credentials or network access, making it particularly dangerous in environments where users may have legitimate access to systems. Once elevated to kernel mode, attackers can bypass all standard security controls including antivirus software, firewall protections, and user access controls, allowing them to install persistent backdoors, extract sensitive data, modify system files, or establish covert communication channels. The vulnerability also presents significant risk to network security as compromised systems can serve as launch points for lateral movement attacks, enabling attackers to spread malware throughout the network infrastructure. According to the MITRE ATT&CK framework, this vulnerability maps to the privilege escalation technique T1068, where adversaries leverage software vulnerabilities to gain higher-level permissions.
Mitigation strategies for CVE-2016-3250 should prioritize immediate patch deployment through Microsoft's regular security updates, as the vulnerability was addressed in the Microsoft security bulletin MS16-072 released in June 2016. Organizations should implement comprehensive patch management procedures to ensure all affected systems receive the necessary security updates promptly. Additionally, system administrators should consider implementing additional security controls such as disabling unnecessary graphics functionality, restricting user privileges where possible, and monitoring for suspicious process behavior that might indicate exploitation attempts. The vulnerability also highlights the importance of maintaining up-to-date security awareness training for users and implementing application whitelisting policies to prevent unauthorized applications from executing on critical systems. Organizations should also conduct regular vulnerability assessments and penetration testing to identify potential exploitation vectors and ensure that their defensive measures remain effective against similar kernel-mode vulnerabilities.