CVE-2018-8239 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 Server 2016, Windows 10, Windows 10 Servers.
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Analysis
by VulDB Data Team • 08/16/2024
The vulnerability identified as CVE-2018-8239 represents a critical information disclosure flaw within the Windows Graphics Device Interface component that has significant implications for system security. This weakness specifically affects Windows Server 2016, Windows 10, and Windows 10 Servers, making it a widespread concern across modern Microsoft operating systems. The issue stems from improper memory handling within the GDI subsystem, which is responsible for rendering graphics and managing display operations in Windows environments. When exploited, this vulnerability allows unauthorized access to sensitive memory contents that should remain protected from external inspection.
The technical root cause of CVE-2018-8239 lies in the Windows GDI component's inadequate validation and memory management practices during graphic rendering operations. The vulnerability manifests when the system processes certain graphic operations that trigger memory access patterns which inadvertently expose kernel-level memory contents to user-mode applications. This improper memory disclosure occurs through mechanisms that should normally maintain strict memory boundaries between different privilege levels, allowing potential attackers to extract information that could reveal system internals, memory layouts, or sensitive data structures. The flaw aligns with CWE-200, which categorizes information exposure vulnerabilities, and specifically demonstrates how improper access control can lead to unauthorized data disclosure.
From an operational impact perspective, this vulnerability creates substantial security risks for affected systems. Attackers who successfully exploit CVE-2018-8239 can potentially obtain sensitive information such as kernel memory addresses, system configuration details, or even partial contents of protected memory regions. This information disclosure can serve as a foundation for more sophisticated attacks, including privilege escalation attempts or further exploitation of other system vulnerabilities. The exposure of memory contents can reveal patterns that aid in bypassing security mechanisms like address space layout randomization or other exploit mitigations. According to ATT&CK framework, this vulnerability maps to techniques involving credential access and privilege escalation through information gathering and system reconnaissance activities.
The exploitation of this vulnerability typically requires an attacker to have some level of user access to the target system, as the GDI component is commonly accessed through standard graphics rendering operations. However, the impact extends beyond simple information disclosure, as the leaked memory contents can provide attackers with valuable insights into system internals that could be leveraged for more advanced attacks. Organizations running affected Windows versions should prioritize applying the relevant security updates from Microsoft to mitigate this risk. The vulnerability demonstrates the critical importance of proper memory management in system components and highlights how even seemingly routine functionality like graphics rendering can pose significant security risks when not properly secured against information leakage attacks.