CVE-2012-1868 in Windows
Summary
by MITRE
Race condition in the thread-creation implementation in win32k.sys in the kernel-mode drivers in Microsoft Windows XP SP3 allows local users to gain privileges via a crafted application, aka "Win32k.sys Race Condition Vulnerability."
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Analysis
by VulDB Data Team • 03/25/2021
The CVE-2012-1868 vulnerability represents a critical race condition flaw within the win32k.sys kernel-mode driver component of Microsoft Windows XP Service Pack 3. This vulnerability specifically targets the thread-creation implementation mechanism that governs how graphical user interface components are managed within the operating system kernel. The race condition occurs when multiple threads attempt to access shared resources simultaneously during the creation and management of graphical objects, creating a temporal window where system integrity can be compromised. This flaw is particularly concerning because it exists at the kernel level, meaning that successful exploitation can lead to complete system compromise and privilege escalation from standard user context to system-level administrator privileges.
The technical implementation of this vulnerability stems from improper synchronization mechanisms within the win32k.sys driver when handling thread creation operations. When a malicious application attempts to create multiple threads simultaneously while interacting with graphical subsystem functions, the race condition allows for unpredictable behavior in resource allocation and object management. This occurs because the driver fails to properly lock or serialize access to critical data structures that store thread information and graphical object states. The flaw is classified under CWE-362, which specifically addresses race conditions in concurrent programming, making it a prime example of improper synchronization in kernel-mode code. Attackers can exploit this by crafting applications that deliberately trigger the race condition through rapid thread creation and destruction patterns, causing the system to allocate memory or resources in an inconsistent state.
The operational impact of CVE-2012-1868 is severe and multifaceted, particularly in enterprise environments where Windows XP systems may still be operational despite end-of-life status. Local privilege escalation through this vulnerability allows attackers to gain SYSTEM-level access, which provides complete control over the affected system including the ability to install malware, modify system files, disable security features, and access all user data. The attack vector is relatively simple to implement as it only requires local user access and does not necessitate network connectivity or complex exploitation techniques. This makes the vulnerability particularly dangerous in scenarios where users have legitimate access to systems but could be compromised through social engineering or other means. The vulnerability's impact aligns with ATT&CK technique T1068, which describes the exploitation of local privilege escalation vulnerabilities, and T1543, which covers the use of kernel-mode rootkits that can leverage such flaws to maintain persistent access.
Mitigation strategies for CVE-2012-1868 should prioritize immediate system hardening and patch management approaches. Microsoft released security updates that addressed this vulnerability through proper synchronization mechanisms in the win32k.sys driver, and organizations should ensure these patches are applied immediately. For systems where patching is not immediately feasible, administrators should implement strict user access controls and disable unnecessary graphical components that could trigger the vulnerable code paths. The principle of least privilege should be enforced, limiting local user capabilities and monitoring for anomalous thread creation patterns that might indicate exploitation attempts. Additionally, system monitoring tools should be configured to detect unusual kernel-mode behavior, and intrusion detection systems should be tuned to identify potential exploitation signatures. Organizations should also consider implementing application whitelisting policies to prevent the execution of malicious applications designed to trigger the race condition, as this vulnerability requires local execution to be effective.