CVE-2019-1485 in Internet Explorer
Summary
by MITRE
A remote code execution vulnerability exists in the way that the VBScript engine handles objects in memory, aka 'VBScript Remote Code Execution Vulnerability'.
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Analysis
by VulDB Data Team • 03/09/2024
The vulnerability identified as CVE-2019-1485 represents a critical remote code execution flaw within Microsoft's VBScript engine implementation. This vulnerability specifically manifests in how the engine processes objects in memory, creating an exploitable condition that allows attackers to execute arbitrary code on affected systems. The flaw exists at the core of Microsoft's scripting engine architecture, where improper memory handling during object manipulation creates opportunities for malicious code injection. This vulnerability affects multiple versions of Windows operating systems including Windows 7, Windows 8.1, Windows Server 2008 R2, Windows Server 2012, Windows Server 2012 R2, and Windows Server 2016. The issue stems from insufficient validation of object references during memory operations, which can be manipulated through crafted malicious scripts.
The technical exploitation of this vulnerability leverages memory corruption techniques that target the VBScript engine's object management subsystem. Attackers can construct malicious VBScript code that triggers buffer overflows or use-after-free conditions when the engine attempts to handle specific object references. This memory handling flaw falls under the CWE-125 vulnerability category, which describes out-of-bounds read conditions that can lead to arbitrary code execution. The vulnerability operates through the Windows Scripting Host component, where VBScript objects are created and managed in memory before being executed. When the engine encounters malformed object references, it fails to properly validate memory boundaries, allowing attackers to overwrite critical memory regions with malicious payloads.
The operational impact of CVE-2019-1485 is severe and far-reaching across enterprise environments. Successful exploitation enables attackers to execute code with the privileges of the current user, potentially leading to full system compromise and lateral movement within networks. This vulnerability is particularly dangerous because it can be triggered through various attack vectors including malicious websites, email attachments, and compromised web applications that execute VBScript code. The vulnerability's remote execution capability means that attackers do not need physical access to target systems, making it an attractive target for automated exploitation campaigns. Organizations using legacy systems or those that have not applied security patches face heightened risk, as this vulnerability can be leveraged to establish persistent backdoors and exfiltrate sensitive data.
Mitigation strategies for CVE-2019-1485 should prioritize immediate patch deployment through Microsoft's security updates, which address the underlying memory handling issues in the VBScript engine. Organizations should implement network segmentation and application whitelisting to prevent unauthorized script execution, particularly disabling VBScript processing in web browsers and email clients. The implementation of exploit prevention measures such as Windows Defender Application Control or similar technologies can provide additional protection layers. Security teams should also monitor for indicators of compromise related to this vulnerability, including unusual network connections, unexpected process creation, and anomalous memory usage patterns. The ATT&CK framework categorizes this vulnerability under T1059.005 for Windows Scripting, making it a target for threat actors seeking to establish persistence through scripting-based attacks. Regular security assessments and vulnerability scanning should be conducted to ensure complete remediation across all affected systems, particularly focusing on legacy Windows environments where patching may be delayed or incomplete.