CVE-2015-2511 in Windows
Summary
by MITRE
The kernel-mode driver in Microsoft Windows Vista SP2, Windows Server 2008 SP2 and R2 SP1, Windows 7 SP1, Windows 8, Windows 8.1, Windows Server 2012 Gold and R2, Windows RT Gold and 8.1, and Windows 10 allows local users to gain privileges via a crafted application, aka "Win32k Memory Corruption Elevation of Privilege Vulnerability," a different vulnerability than CVE-2015-2517, CVE-2015-2518, and CVE-2015-2546.
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Analysis
by VulDB Data Team • 07/06/2025
The vulnerability identified as CVE-2015-2511 represents a critical privilege escalation flaw within the Windows kernel-mode driver subsystem, specifically affecting multiple versions of the windows operating system from vista through windows 10. This vulnerability resides in the win32k.sys driver which manages user interface components and graphics rendering functions in the kernel space, making it a prime target for attackers seeking to elevate their privileges from standard user level to system level access. The flaw manifests as a memory corruption issue that occurs when the driver processes certain crafted inputs, creating an exploitable condition that can be leveraged by local malicious applications to execute arbitrary code with elevated privileges.
The technical nature of this vulnerability stems from improper validation of user-supplied data within the win32k.sys driver, which operates in kernel mode and handles critical graphics and user interface operations. When a malicious application presents crafted parameters to the driver through legitimate system calls, the driver fails to properly validate these inputs, leading to memory corruption that can be manipulated to redirect execution flow. This memory corruption vulnerability falls under the CWE-121 category of stack-based buffer overflow, though the specific implementation involves heap corruption within kernel-mode memory structures. The vulnerability allows attackers to exploit the driver's handling of graphics objects and user interface elements to achieve privilege escalation without requiring network connectivity or external attack vectors.
The operational impact of CVE-2015-2511 is severe as it enables local attackers who already have user-level access to escalate their privileges to system level without requiring additional attack vectors or network access. This makes the vulnerability particularly dangerous in environments where users may have legitimate access to systems but where privilege escalation could lead to complete system compromise. Attackers can leverage this vulnerability to install persistent backdoors, modify system files, access sensitive data, and establish footholds for further lateral movement within networks. The vulnerability affects all supported versions of windows from vista through windows 10, making it a widespread concern for organizations maintaining legacy systems. According to ATT&CK framework, this vulnerability maps to privilege escalation techniques under the T1068 category, specifically targeting kernel-mode exploits to achieve system-level access.
Mitigation strategies for CVE-2015-2511 primarily involve applying the official microsoft security patches released as part of the may 2015 security updates. Organizations should prioritize immediate deployment of these patches across all affected systems, particularly those running vulnerable windows versions. Additionally, implementing security measures such as user access controls, disabling unnecessary user accounts, and maintaining up-to-date antivirus signatures can help reduce the attack surface. The vulnerability can also be mitigated through kernel-mode exploit prevention techniques including disabling unnecessary graphics drivers, implementing application whitelisting, and monitoring for suspicious system calls that may indicate exploitation attempts. Organizations should also consider implementing behavioral monitoring solutions that can detect anomalous privilege escalation activities that might indicate exploitation of this vulnerability, as the attack surface remains significant due to the widespread nature of affected windows versions.