CVE-2011-1879 in Windows
Summary
by MITRE
Use-after-free vulnerability in win32k.sys in the kernel-mode drivers in Microsoft Windows XP SP2 and SP3, Windows Server 2003 SP2, Windows Vista SP1 and SP2, Windows Server 2008 Gold, SP2, R2, and R2 SP1, and Windows 7 Gold and SP1 allows local users to gain privileges via a crafted application that leverages incorrect driver object management, a different vulnerability than other CVEs listed in MS11-054, aka "Win32k Use After Free Vulnerability."
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Analysis
by VulDB Data Team • 11/14/2021
The CVE-2011-1879 vulnerability represents a critical use-after-free flaw in the win32k.sys kernel-mode driver component of Microsoft Windows operating systems. This vulnerability specifically affects Windows XP SP2 and SP3, Windows Server 2003 SP2, Windows Vista SP1 and SP2, Windows Server 2008 Gold, SP2, R2, and R2 SP1, as well as Windows 7 Gold and SP1. The flaw stems from improper management of driver objects within the kernel-mode execution context, creating a scenario where freed memory locations can be accessed and manipulated by malicious code. This particular vulnerability operates at the kernel level, making it exceptionally dangerous as it can potentially elevate privileges from standard user context to SYSTEM level access, which represents the highest privilege level in Windows operating systems.
The technical implementation of this vulnerability involves a race condition or improper memory management within the win32k.sys driver that handles user interface components and window management functions. When a crafted application interacts with the vulnerable driver through specific API calls, it can trigger the release of memory resources while simultaneously allowing subsequent access to those same memory locations. This creates a window where malicious code can overwrite freed memory with malicious payloads, potentially leading to arbitrary code execution. The vulnerability is classified as a use-after-free under CWE-416, which specifically addresses the use of memory after it has been freed, a common class of memory safety vulnerabilities that frequently leads to privilege escalation and system compromise. The flaw operates within the Windows kernel-mode environment, making it particularly challenging to detect and exploit, as it bypasses typical user-mode security controls and protections.
The operational impact of this vulnerability extends beyond simple privilege escalation, as it can serve as a foundational exploit for more sophisticated attacks within the Windows ecosystem. Local attackers who can execute code on a vulnerable system can leverage this vulnerability to gain SYSTEM-level privileges, effectively compromising the entire operating system. The exploitability of this vulnerability is enhanced by the fact that it requires minimal user interaction, as the malicious application can be crafted to trigger the vulnerability automatically. This makes it particularly dangerous in environments where users might inadvertently run malicious software, and it can be weaponized in various attack scenarios including malware delivery, credential theft, and persistent backdoor establishment. The vulnerability's presence in multiple Windows versions from XP through Windows 7 demonstrates its widespread impact and the need for comprehensive patch management across legacy systems.
Mitigation strategies for CVE-2011-1879 should focus on immediate patch deployment as provided by Microsoft through security updates, particularly MS11-054 which specifically addresses this vulnerability. Organizations must ensure that all affected systems receive the relevant security patches and updates, with particular attention to legacy systems that may not receive support for newer security measures. Additionally, implementing kernel-mode exploit protection mechanisms such as Data Execution Prevention (DEP), Address Space Layout Randomization (ASLR), and Control Flow Guard (CFG) can provide additional layers of defense against exploitation attempts. Network administrators should also consider implementing application whitelisting policies to prevent execution of unauthorized applications that might attempt to exploit this vulnerability. From an ATT&CK framework perspective, this vulnerability aligns with techniques such as privilege escalation through kernel exploits and defense evasion through process injection, making it a critical target for both prevention and detection efforts within enterprise security architectures. The vulnerability serves as a prime example of why maintaining up-to-date security patches and implementing comprehensive security monitoring is essential for protecting against kernel-level exploits that can fundamentally compromise system integrity.