CVE-2016-7260 in Windows
Summary
by MITRE
The kernel-mode drivers in Microsoft Windows Vista SP2, Windows Server 2008 SP2 and R2 SP1, Windows 7 SP1, Windows 8.1, Windows Server 2012 Gold and R2, Windows RT 8.1, Windows 10 Gold, 1511, and 1607, and Windows Server 2016 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 • 10/08/2022
The vulnerability identified as CVE-2016-7260 represents a critical privilege escalation flaw within the Windows kernel-mode drivers, specifically affecting the win32k.sys component that manages user interface elements and graphics rendering. This issue stems from improper handling of user-mode input validation within the graphics subsystem, creating a pathway for local attackers to execute code with elevated privileges. The affected systems span multiple Windows versions including Vista through Windows 10, making this vulnerability particularly widespread and impactful across enterprise environments.
The technical root cause of this vulnerability lies in the improper validation of user-mode input parameters within the win32k.sys driver, which is responsible for managing the Windows graphical subsystem. When applications interact with the graphics subsystem through user-mode interfaces, the kernel-mode driver fails to properly validate certain parameters, allowing malicious input to bypass security checks. This flaw specifically affects the handling of graphics objects and their associated memory structures, enabling attackers to manipulate kernel memory through crafted applications that leverage the graphics rendering pipeline. The vulnerability is categorized under CWE-121 as a stack-based buffer overflow, though the actual exploitation involves more complex memory manipulation techniques.
The operational impact of CVE-2016-7260 is severe, as it allows local users to escalate their privileges from standard user level to SYSTEM level access without requiring additional authentication or network connectivity. Attackers can exploit this vulnerability by creating a malicious application that triggers the flawed graphics handling code path, potentially leading to complete system compromise. The vulnerability is particularly dangerous in enterprise environments where users may have legitimate access to systems but lack administrative privileges, as successful exploitation would grant attackers full control over affected machines. This privilege escalation capability directly maps to ATT&CK technique T1068, which covers local privilege escalation through kernel-mode exploits, and T1547, covering registry run keys and startup folder modifications that attackers might employ post-exploitation.
Mitigation strategies for this vulnerability require immediate patch application from Microsoft, as the primary solution involves installing the security updates released in the July 2016 security bulletin. Organizations should prioritize patching all affected Windows versions, particularly those in production environments where local access is possible. Additional defensive measures include implementing application whitelisting policies to prevent execution of unauthorized applications, monitoring for suspicious graphics-related API calls, and conducting regular security assessments of user access controls. Network segmentation and least privilege principles should be enforced to limit potential attack surfaces, while security teams should monitor for indicators of compromise related to unauthorized privilege escalation attempts. The vulnerability also highlights the importance of kernel-mode exploit mitigation techniques such as driver signature enforcement and exploit protection features that can help prevent exploitation even when patches are not immediately available.