CVE-2017-8491 in Windows
Summary
by MITRE
The kernel in Microsoft Windows Server 2008 SP2 and R2 SP1, Windows 7 SP1, Windows 8.1, Windows Server 2012 Gold and R2, Windows RT 8.1, Windows 10 Gold, 1511, 1607, 1703, and Windows Server 2016 allows an authenticated attacker to obtain information via a specially crafted application. aka "Windows Kernel Information Disclosure Vulnerability," a different vulnerability than CVE-2017-8492, CVE-2017-8490, CVE-2017-8489, CVE-2017-8488, CVE-2017-8485, CVE-2017-8483, CVE-2017-8482, CVE-2017-8480, CVE-2017-8479, CVE-2017-8478, CVE-2017-8476, CVE-2017-8474, CVE-2017-8469, CVE-2017-8462, CVE-2017-0300, CVE-2017-0299, and CVE-2017-0297.
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Analysis
by VulDB Data Team • 08/20/2024
The vulnerability identified as CVE-2017-8491 represents a critical information disclosure flaw within the Windows kernel implementation that affects multiple versions of Microsoft operating systems including Windows Server 2008 SP2 and R2 SP1, Windows 7 SP1, Windows 8.1, Windows Server 2012 Gold and R2, Windows RT 8.1, Windows 10 Gold, 1511, 1607, 1703, and Windows Server 2016. This vulnerability falls under the category of information disclosure weaknesses that can potentially expose sensitive kernel memory contents to authenticated attackers. The flaw specifically resides in how the kernel handles certain data structures and memory management operations, creating opportunities for adversaries to extract confidential information that could aid in further exploitation attempts. The vulnerability is particularly concerning because it operates at the kernel level where privilege escalation and system compromise become significantly more feasible once sensitive information is obtained.
The technical mechanism behind CVE-2017-8491 involves improper handling of kernel memory structures during specific operations that allow authenticated users to read memory locations that should remain protected. This information disclosure occurs through a specially crafted application that exploits weaknesses in the kernel's memory management subsystem. The vulnerability demonstrates characteristics consistent with CWE-200, which defines information exposure as a weakness where information is accessible to unauthorized actors. The flaw enables attackers to potentially extract kernel pointers, memory addresses, or other sensitive data that could be used to bypass security mechanisms like address space layout randomization and data execution prevention. This type of information leakage creates a foundation for more sophisticated attacks by providing attackers with insights into system memory layout and kernel structures that would otherwise remain hidden from normal user-space operations.
The operational impact of this vulnerability extends beyond simple information disclosure, as it creates opportunities for advanced persistent threats and privilege escalation attacks. An authenticated attacker with local access can leverage this vulnerability to gather detailed information about the kernel's internal state, which can then be used to plan subsequent attacks against the system. The vulnerability affects systems running various Windows versions simultaneously, making it a widespread concern across enterprise environments where multiple operating system versions coexist. Security researchers have noted that this vulnerability can be particularly dangerous in environments where Windows systems are not regularly updated, as the information disclosure can provide attackers with the exact kernel versions and memory layouts they need to craft targeted exploits. The attack surface is broad since any authenticated user, including regular domain users, can potentially trigger this vulnerability without requiring administrative privileges, making it a significant concern for organizations with less stringent access controls.
Mitigation strategies for CVE-2017-8491 should focus on immediate patching of affected systems and implementation of additional security controls to limit the attack surface. Microsoft released security updates that address this vulnerability, and organizations should prioritize deployment of these patches across all affected systems. Network segmentation and access controls should be implemented to reduce the potential impact of authenticated attacks, particularly in environments where users may have elevated privileges. Monitoring systems should be configured to detect unusual memory access patterns or attempts to read kernel structures that could indicate exploitation attempts. The vulnerability aligns with several ATT&CK techniques including privilege escalation and defense evasion, where adversaries may use information disclosure to bypass security controls. Organizations should also implement regular vulnerability assessments and penetration testing to identify potential exploitation paths that could leverage this information disclosure for more serious attacks. Additionally, implementing kernel-mode exploit protection mechanisms and ensuring that systems are not running outdated or unsupported Windows versions can significantly reduce the risk exposure associated with this vulnerability.