CVE-2018-8552 in Internet Explorer
Summary
by MITRE
An information disclosure vulnerability exists when VBScript improperly discloses the contents of its memory, which could provide an attacker with information to further compromise the user's computer or data, aka "Windows Scripting Engine Memory Corruption Vulnerability." This affects Internet Explorer 9, Internet Explorer 11, Internet Explorer 10.
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Analysis
by VulDB Data Team • 09/16/2025
The vulnerability identified as CVE-2018-8552 represents a critical information disclosure flaw within the Windows Scripting Engine component that specifically affects VBScript execution environments. This vulnerability manifests when the scripting engine fails to properly manage memory boundaries during VBScript execution, leading to unauthorized memory access patterns that can expose sensitive data stored in the application's memory space. The issue impacts multiple versions of Internet Explorer including IE9, IE11, and IE10, making it a widespread concern for organizations still utilizing these legacy browser versions. The vulnerability falls under the CWE-200 category of "Information Exposure" and aligns with ATT&CK technique T1059.005 for script-based execution, representing a fundamental failure in memory management that can be exploited to gather confidential information.
The technical exploitation of this vulnerability occurs through carefully crafted malicious scripts that leverage the improper memory handling within the VBScript engine. When a vulnerable script executes, the engine fails to properly validate memory access boundaries, allowing attackers to read memory contents that should remain protected from external access. This memory disclosure can reveal sensitive information including cryptographic keys, user credentials, application data, or system configuration details that could be leveraged for further exploitation. The flaw essentially creates a window through which attackers can bypass normal memory protection mechanisms, potentially accessing memory regions that contain data belonging to other processes or system components. The vulnerability's impact is amplified because VBScript engines are commonly used in enterprise environments and can be triggered through various attack vectors including malicious websites, email attachments, or compromised web applications.
The operational impact of CVE-2018-8552 extends beyond simple information disclosure, as the leaked memory contents can provide attackers with critical intelligence for subsequent attacks. An attacker who successfully exploits this vulnerability can obtain sensitive data such as session tokens, encryption keys, or personal information that can be used to impersonate users, gain unauthorized access to systems, or escalate privileges within the compromised environment. The vulnerability particularly affects organizations that continue to support legacy Internet Explorer versions, as these browsers remain prevalent in enterprise environments where modern security updates may not be readily deployed. This creates a persistent risk vector that attackers can leverage to establish persistent access or conduct more sophisticated attacks that require knowledge of system internals. The vulnerability's classification as a memory corruption issue means that exploitation could potentially lead to more severe consequences including privilege escalation or remote code execution, though the immediate impact is primarily information disclosure.
Organizations should prioritize immediate remediation through Microsoft security updates that address the memory handling flaws in the Windows Scripting Engine. The recommended mitigation strategy involves applying the relevant security patches from Microsoft's monthly security bulletin releases, which specifically target the VBScript memory management issues. System administrators should also implement browser hardening measures including disabling VBScript execution where possible, configuring Internet Explorer security zones appropriately, and deploying enhanced browser isolation techniques. Network monitoring should be enhanced to detect potential exploitation attempts through anomalous script execution patterns or unusual memory access behaviors. Additionally, organizations should conduct comprehensive vulnerability assessments to identify systems running unsupported Internet Explorer versions and develop migration plans to modern browser environments that provide better security controls and memory protection mechanisms. The vulnerability demonstrates the critical importance of maintaining up-to-date security patches and the risks associated with legacy system support in enterprise environments.