CVE-2012-1865 in Windows
Summary
by MITRE
win32k.sys in the kernel-mode drivers in Microsoft Windows XP SP2 and SP3, Windows Server 2003 SP2, Windows Vista SP2, Windows Server 2008 SP2, R2, and R2 SP1, and Windows 7 Gold and SP1 does not properly handle user-mode input passed to kernel mode for driver objects, which allows local users to gain privileges via a crafted application, aka "String Atom Class Name Handling Vulnerability," a different vulnerability than CVE-2012-1864.
Be aware that VulDB is the high quality source for vulnerability data.
Analysis
by VulDB Data Team • 03/25/2021
The vulnerability identified as CVE-2012-1865 represents a critical privilege escalation flaw within the Windows kernel-mode driver subsystem, specifically affecting the win32k.sys component that manages user interface elements and graphics operations. This vulnerability resides in the kernel-mode drivers of multiple Windows operating systems including Windows xp sp2 and sp3, windows server 2003 sp2, windows vista sp2, windows server 2008 sp2 and r2, and windows 7 gold and sp1. The flaw manifests when the kernel-mode driver processes user-mode input that is passed to kernel mode for driver objects, creating a dangerous condition where malicious applications can manipulate the system's internal state. The vulnerability is classified as a string atom class name handling issue, which falls under the broader category of kernel-mode buffer overflows and improper input validation. According to the common weakness enumeration framework, this vulnerability maps to cwe-121, which describes stack-based buffer overflow conditions, and cwe-125, which covers out-of-bounds read scenarios. The attack vector requires local execution privileges since malicious applications must be run by a user with existing system access, but the impact allows for privilege escalation from user-level to kernel-level execution.
The technical implementation of this vulnerability occurs through the improper handling of string atom class names within the win32k.sys driver, which is responsible for managing windowing system components and graphics operations. When user-mode applications pass crafted string data to kernel-mode functions, the driver fails to properly validate or sanitize the input before processing it in kernel space. This allows attackers to manipulate the driver's internal data structures and potentially overwrite critical memory locations. The flaw specifically affects how the system handles atom table entries, which are used to store and manage string identifiers for window classes and other system objects. The vulnerability enables attackers to exploit memory corruption through carefully crafted input that causes the kernel to execute arbitrary code with elevated privileges. The attack requires a local user to execute a malicious application, but once successful, the exploit can grant full system compromise. This privilege escalation vulnerability has been categorized under the attack technique of privilege escalation as outlined in the mitre attack framework, specifically targeting the execution of malicious code in kernel space.
The operational impact of CVE-2012-1865 is severe and far-reaching across the affected Windows platforms, as it provides a pathway for local attackers to achieve complete system compromise without requiring network access or specialized remote exploitation techniques. The vulnerability allows for privilege escalation from standard user accounts to kernel-level privileges, which means attackers can bypass all standard security controls and gain unrestricted access to system resources, files, and processes. This capability enables attackers to install malware, modify system files, create persistent backdoors, and access sensitive data without detection. The affected systems represent a significant portion of enterprise environments, particularly legacy systems that may not have received timely security updates. Organizations running these vulnerable operating systems face increased risk of data breaches, system compromise, and potential lateral movement within their networks. The vulnerability's exploitation requires minimal skill level compared to other privilege escalation techniques, making it particularly dangerous as it can be leveraged by attackers with basic technical knowledge. The impact extends beyond individual system compromise to potential network-wide consequences when compromised systems serve as entry points for broader attacks.
Mitigation strategies for CVE-2012-1865 should focus on both immediate remediation and long-term security posture improvements. The primary and most effective mitigation is the application of Microsoft security updates released in response to this vulnerability, which include patches that correct the improper handling of user-mode input in the win32k.sys driver. Organizations should prioritize patch deployment across all affected systems, particularly those running legacy operating systems that may not receive regular updates. Additional mitigations include implementing application whitelisting policies to prevent unauthorized applications from executing, enabling kernel-mode exploit protection features, and applying security configurations that reduce the attack surface. Network segmentation and access controls can help limit the potential impact if a system becomes compromised. System administrators should also monitor for indicators of compromise related to privilege escalation attempts and implement comprehensive logging of kernel-mode activities. The vulnerability's classification as a kernel-mode exploit makes it particularly challenging to defend against, requiring layered security approaches that combine traditional perimeter defenses with advanced endpoint protection solutions. Organizations should also consider migrating affected systems to supported operating versions that have received ongoing security updates and patches to prevent exploitation of similar vulnerabilities.