CVE-2012-0005 in Windows
Summary
by MITRE
The Client/Server Run-time Subsystem (aka CSRSS) in the Win32 subsystem in Microsoft Windows XP SP2 and SP3, Server 2003 SP2, Vista SP2, and Server 2008 SP2, when a Chinese, Japanese, or Korean system locale is used, can access uninitialized memory during the processing of Unicode characters, which allows local users to gain privileges via a crafted application, aka "CSRSS Elevation of Privilege Vulnerability."
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Analysis
by VulDB Data Team • 01/05/2025
The CSRSS elevation of privilege vulnerability represents a critical security flaw within Microsoft Windows operating systems that specifically manifests when systems utilize Chinese, Japanese, or Korean language locales. This vulnerability resides in the Client/Server Run-time Subsystem component which serves as a fundamental part of the Win32 subsystem responsible for managing console windows and process creation. The flaw occurs during Unicode character processing when the subsystem accesses memory locations that have not been properly initialized, creating a potential pathway for privilege escalation attacks.
The technical exploitation of this vulnerability leverages the specific handling of Unicode characters in the context of East Asian language locales where the system processes complex character sets that require special memory management routines. When CSRSS encounters certain Unicode sequences, it fails to properly initialize memory structures before accessing them, leading to potential information disclosure and privilege escalation opportunities. This memory access pattern creates a condition where malicious applications can manipulate the system to execute code with elevated privileges, effectively bypassing standard security boundaries that normally prevent local users from gaining administrative access.
The operational impact of this vulnerability extends beyond simple privilege escalation as it fundamentally compromises the security model of affected Windows versions. Attackers can leverage this flaw to execute malicious code with system-level privileges, potentially leading to complete system compromise, data theft, or persistent backdoor installation. The vulnerability affects multiple Windows versions including Windows xp sp2 and sp3, server 2003 sp2, vista sp2, and server 2008 sp2, making it particularly widespread in enterprise environments where these older systems remain operational. The localized nature of the vulnerability means that systems configured with Chinese, Japanese, or Korean language settings are at heightened risk, though the underlying memory management flaw affects all affected platforms equally.
Microsoft addressed this vulnerability through security updates that properly initialize memory structures during Unicode processing within the CSRSS component. Organizations should implement these patches immediately and consider additional mitigations such as restricting local user privileges, implementing application whitelisting, and monitoring for suspicious process behavior. The vulnerability aligns with CWE-457: Use of Uninitialized Variable and represents a classic example of how improper memory management can lead to privilege escalation attacks. From an attack perspective, this vulnerability fits within the ATT&CK technique of privilege escalation through exploitation of software vulnerabilities, specifically targeting the Windows kernel and subsystem components that control system-level operations and access controls.