CVE-2015-0060 in Windows
Summary
by MITRE
The font mapper in win32k.sys in the kernel-mode drivers in Microsoft Windows Server 2003 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 does not properly scale fonts, which allows local users to cause a denial of service (system hang) via a crafted application, aka "Windows Font Driver Denial of Service Vulnerability."
If you want to get best quality of vulnerability data, you may have to visit VulDB.
Analysis
by VulDB Data Team • 06/09/2025
The vulnerability described in CVE-2015-0060 resides within the kernel-mode font mapping functionality of Microsoft Windows operating systems, specifically within the win32k.sys driver component. This critical flaw affects a broad range of Windows versions including server and client operating systems from Windows vista through Windows 8.1, making it a widespread concern across enterprise and desktop environments. The vulnerability is classified as a denial of service issue that can be exploited by local attackers through crafted applications, potentially leading to system instability and complete system hangs that require manual intervention to resolve.
The technical root cause of this vulnerability lies in improper font scaling mechanisms within the kernel-mode font mapper component. When processing font data, the win32k.sys driver fails to correctly handle certain font parameters during the scaling operation, leading to memory corruption or resource exhaustion conditions. This flaw specifically manifests when applications attempt to render fonts with malformed or specially crafted parameters that trigger the vulnerable code path in the kernel driver. The improper handling occurs during the font mapping process where the system attempts to scale font glyphs to different sizes, and the insufficient validation leads to unpredictable behavior that can result in system crashes or complete system freezes.
From an operational perspective, this vulnerability presents significant risk to organizations as it allows local users to cause system-wide denial of service conditions without requiring elevated privileges. The attack vector is particularly concerning because it only requires a local user to execute a malicious application, eliminating the need for network-based exploitation or complex attack chains. System administrators face the challenge of maintaining service availability when such vulnerabilities are exploited, as the affected systems may become completely unresponsive until manual reboot is performed. The impact extends beyond simple service disruption to potentially affect productivity and business continuity, especially in environments where system uptime is critical.
The vulnerability aligns with CWE-121, which describes heap-based buffer overflow conditions, and maps to ATT&CK technique T1499.004 for denial of service attacks. Organizations should implement immediate mitigation strategies including applying Microsoft security patches, implementing application whitelisting to prevent execution of untrusted applications, and monitoring for suspicious font processing activities. System hardening measures such as disabling unnecessary font rendering capabilities and restricting local user privileges can also reduce the attack surface. Additionally, network segmentation and monitoring solutions should be configured to detect anomalous font processing patterns that may indicate exploitation attempts. The vulnerability underscores the importance of maintaining up-to-date security patches and implementing defense-in-depth strategies to protect against kernel-mode exploits that can compromise entire operating system functionalities.