CVE-2018-8394 in Windows
Summary
by MITRE
An information disclosure vulnerability exists when the Windows GDI component improperly discloses the contents of its memory, aka "Windows GDI Information Disclosure Vulnerability." This affects Windows 7, Windows Server 2012 R2, Windows RT 8.1, Windows Server 2008, Windows Server 2012, Windows 8.1, Windows Server 2016, Windows Server 2008 R2, Windows 10, Windows 10 Servers. This CVE ID is unique from CVE-2018-8396, CVE-2018-8398.
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Analysis
by VulDB Data Team • 07/15/2024
The vulnerability identified as CVE-2018-8394 represents a critical information disclosure flaw within the Windows Graphics Device Interface (GDI) component that enables unauthorized access to sensitive memory contents. This issue stems from improper handling of memory operations within the GDI subsystem, which is responsible for rendering graphics and managing display operations across the Windows operating system. The vulnerability specifically manifests when the GDI component fails to properly validate or sanitize memory access patterns, potentially exposing kernel-mode memory structures to user-mode applications.
From a technical perspective, this vulnerability operates at the kernel level within the Windows operating system, making it particularly dangerous as it can be exploited by malicious actors to extract sensitive information from system memory. The GDI component's improper memory handling creates a pathway for information leakage that can reveal critical system data including kernel pointers, memory layout information, and potentially other confidential data that could be leveraged in subsequent attacks. This type of vulnerability falls under the CWE-200 category of "Information Exposure" and represents a fundamental breakdown in the memory protection mechanisms that should prevent user-mode processes from accessing kernel memory spaces.
The operational impact of CVE-2018-8394 extends across multiple Windows operating system versions, including legacy systems such as Windows 7, Windows Server 2008, and Windows Server 2008 R2, as well as newer versions like Windows 10 and Windows Server 2016. This broad affected scope makes the vulnerability particularly concerning for enterprise environments where older systems may still be in operation. The vulnerability can be exploited through various attack vectors including malicious documents, web content, or by leveraging other initial compromise techniques that allow an attacker to execute code within the GDI context. According to ATT&CK framework, this vulnerability maps to T1059.007 for Windows Command Shell and potentially T1068 for local privilege escalation if combined with other exploitation techniques.
The exploitation of this vulnerability can lead to significant security implications including potential privilege escalation, memory corruption, and the extraction of sensitive information that could be used to bypass security controls or facilitate further attacks. Attackers can potentially use the leaked memory information to perform address space layout randomization (ASLR) bypasses, which are commonly used to defeat modern exploit mitigations. The vulnerability's classification as an information disclosure issue means that while it may not directly enable code execution, it provides attackers with crucial information needed to craft more sophisticated attacks against the affected systems. Organizations should consider implementing additional security controls such as exploit protection rules, application whitelisting, and network segmentation to mitigate the risk associated with this vulnerability. Microsoft addressed this issue through security updates that improved memory validation within the GDI component, but system administrators must ensure all affected systems receive these patches promptly to prevent exploitation.