CVE-2015-1726 in Windows
Summary
by MITRE
Use-after-free vulnerability in the kernel-mode drivers in Microsoft Windows Server 2003 SP2 and R2 SP2, Windows Vista SP2, Windows Server 2008 SP2 and R2 SP1, Windows 7 SP1, Windows 8, Windows 8.1, Windows Server 2012 Gold and R2, and Windows RT Gold and 8.1 allows local users to gain privileges via a crafted application, aka "Microsoft Windows Kernel Brush Object Use After Free Vulnerability."
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Analysis
by VulDB Data Team • 07/06/2025
This vulnerability resides in the kernel-mode drivers of multiple Microsoft Windows operating systems, specifically affecting versions including Windows Server 2003 SP2 and R2 SP2, Windows Vista SP2, Windows Server 2008 SP2 and R2 SP1, Windows 7 SP1, Windows 8, Windows 8.1, Windows Server 2012 Gold and R2, and Windows RT Gold and 8.1. The flaw manifests as a use-after-free condition in the kernel-mode driver handling of brush objects, which represents a critical security weakness that can be exploited by local attackers to escalate privileges. The vulnerability stems from improper memory management where freed memory locations are still accessed or referenced after being deallocated, creating opportunities for malicious code execution with elevated privileges. This type of vulnerability falls under CWE-416, which specifically addresses Use After Free conditions in software development. The attack vector requires a local user to execute a crafted application that triggers the memory management flaw in the kernel drivers responsible for handling graphical brush objects. When the kernel driver processes these objects, it fails to properly validate or manage memory references, allowing an attacker to manipulate the freed memory location and potentially execute arbitrary code with kernel-level privileges.
The operational impact of this vulnerability extends beyond simple privilege escalation, as it provides attackers with complete control over the affected systems. The use-after-free condition in kernel-mode drivers creates a path for attackers to bypass standard security boundaries and execute malicious code with the highest possible system privileges. This vulnerability can be particularly dangerous in enterprise environments where local users might have access to systems that are otherwise protected by network security measures. The exploitation typically involves crafting a malicious application that carefully manipulates the brush object handling in the kernel driver, causing memory to be freed and then accessed in an unauthorized manner. Attackers can leverage this to install backdoors, modify system files, disable security features, or establish persistent access to compromised systems. The vulnerability's presence across multiple Windows versions indicates a widespread issue that affects both server and client operating systems, making it a significant concern for organizations maintaining legacy systems. According to ATT&CK framework, this vulnerability maps to privilege escalation techniques and specifically relates to T1068, which covers 'Local Privilege Escalation' and T1543, which addresses 'Create or Modify System Process' through kernel-mode exploitation.
Mitigation strategies for this vulnerability require immediate patching of affected systems, as Microsoft released security updates addressing this specific use-after-free condition in their regular security bulletins. Organizations should prioritize patch management to ensure all affected Windows versions receive the necessary security updates that correct the memory management flaws in the kernel-mode drivers. System administrators should also implement additional security controls such as enabling kernel-mode driver verification, implementing application whitelisting policies, and monitoring for suspicious kernel-mode activity that might indicate exploitation attempts. The vulnerability's nature as a kernel-mode flaw makes traditional user-mode security controls ineffective, emphasizing the need for comprehensive system hardening measures. Organizations should also consider implementing runtime application protection mechanisms and enhanced monitoring of system calls related to memory management operations. Additionally, the principle of least privilege should be enforced to minimize the impact of potential exploitation, ensuring that local user accounts have only the minimum necessary permissions to perform their required functions. Regular security assessments and vulnerability scanning should be conducted to identify systems running affected versions of Windows that may not have received the necessary patches, particularly in environments with legacy systems that might not automatically receive updates. The vulnerability serves as a reminder of the critical importance of maintaining up-to-date security patches and the potential consequences of running unsupported or unpatched operating systems in enterprise environments.