CVE-2015-0058 in Windows
Summary
by MITRE
Double free vulnerability in win32k.sys in the kernel-mode drivers in Microsoft Windows 8.1, Windows Server 2012 R2, and Windows RT 8.1 allows local users to gain privileges via a crafted application, aka "Windows Cursor Object Double Free Vulnerability."
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Analysis
by VulDB Data Team • 06/12/2025
The CVE-2015-0058 vulnerability represents a critical double free error in the win32k.sys kernel-mode driver component of Microsoft Windows operating systems. This flaw exists within the graphics subsystem responsible for handling cursor objects and user interface elements, making it particularly dangerous as it can be exploited through seemingly benign applications. The vulnerability affects Windows 8.1, Windows Server 2012 R2, and Windows RT 8.1 systems, where the kernel-mode driver fails to properly validate memory management operations when processing cursor objects. The double free condition occurs when the same memory block is freed twice, leading to potential memory corruption that can be leveraged by malicious actors. This type of vulnerability falls under CWE-415, which specifically addresses double free conditions in memory management, and aligns with ATT&CK technique T1068 which covers local privilege escalation through kernel exploits.
The technical exploitation of this vulnerability requires a local attacker to craft a malicious application that can trigger the double free condition within the win32k.sys driver. When a cursor object is processed in the kernel context, the driver improperly handles memory deallocation, causing the same memory block to be freed twice. This memory corruption can be manipulated to overwrite critical kernel data structures or execute arbitrary code with kernel-level privileges. The vulnerability is particularly concerning because it operates within the kernel-mode context, meaning successful exploitation results in complete system compromise without requiring network connectivity or user interaction beyond executing the malicious application. The attack vector is classified as local privilege escalation, where an attacker with low-privilege user access can elevate their privileges to SYSTEM level.
The operational impact of CVE-2015-0058 extends beyond simple privilege escalation, as it represents a fundamental flaw in the Windows kernel's memory management subsystem. Once exploited, attackers can gain complete control over affected systems, enabling them to install malware, modify system files, access sensitive data, or establish persistent backdoors. The vulnerability's presence in multiple Windows versions including server environments makes it particularly dangerous for enterprise networks where these systems are commonly deployed. Organizations running affected Windows versions face significant risk of unauthorized access and potential data breaches, as the exploit can be used to bypass traditional security controls. The vulnerability also demonstrates the challenges of maintaining secure kernel-mode drivers, as even minor memory management flaws can result in complete system compromise.
Mitigation strategies for CVE-2015-0058 should focus on immediate patch deployment through Microsoft's security updates, as the vendor released patches specifically addressing this double free condition in win32k.sys. System administrators should prioritize patching affected Windows 8.1, Windows Server 2012 R2, and Windows RT 8.1 systems to prevent exploitation. Additionally, implementing application whitelisting controls can help prevent execution of malicious applications that might attempt to exploit this vulnerability. Network segmentation and privilege separation should be maintained to limit potential lateral movement if exploitation occurs. Security monitoring should include detection of anomalous cursor object behavior or memory allocation patterns that might indicate exploitation attempts. Organizations should also consider implementing exploit prevention technologies and maintaining up-to-date threat intelligence to identify potential exploitation attempts targeting this specific vulnerability. The vulnerability highlights the importance of maintaining secure kernel-mode operations and proper memory management practices in operating system components.