CVE-2019-1034 in Office
Summary
by MITRE
A remote code execution vulnerability exists in Microsoft Word software when it fails to properly handle objects in memory, aka 'Microsoft Word Remote Code Execution Vulnerability'. This CVE ID is unique from CVE-2019-1035.
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Analysis
by VulDB Data Team • 05/21/2025
The vulnerability identified as CVE-2019-1034 represents a critical remote code execution flaw in Microsoft Word software that stems from improper handling of memory objects during document processing operations. This vulnerability specifically affects Microsoft Word applications across multiple versions and operating systems, creating a significant attack surface for malicious actors who seek to compromise systems through document-based exploits. The flaw manifests when Word encounters specially crafted objects within document files that trigger memory corruption conditions, allowing attackers to execute arbitrary code on vulnerable systems with the privileges of the current user. This particular vulnerability is classified under CWE-125 as an out-of-bounds read condition, which occurs when Word attempts to access memory locations beyond the intended bounds of allocated objects, leading to unpredictable behavior and potential code execution opportunities.
The technical exploitation of CVE-2019-1034 typically involves crafting malicious Word documents that contain malformed objects designed to trigger the memory handling flaw during document rendering or processing. Attackers can deliver these malicious documents through various vectors including email attachments, web downloads, or compromised document repositories. When a user opens such a document, Word's memory management routines fail to properly validate or sanitize the malformed objects, resulting in memory corruption that can be leveraged to inject and execute malicious code within the context of the Word application process. The vulnerability's remote execution capability means that no local system interaction beyond opening the malicious document is required for exploitation, making it particularly dangerous in enterprise environments where users may inadvertently open compromised documents. This behavior aligns with ATT&CK technique T1204.002 for 'User Execution: Malicious File' and T1059.001 for 'Command and Scripting Interpreter: PowerShell' when attackers utilize the compromised system for further malicious activities.
The operational impact of CVE-2019-1034 extends beyond simple code execution, as successful exploitation can lead to complete system compromise and persistent access for threat actors. Once executed, the malicious code can establish backdoors, download additional payloads, or escalate privileges to gain administrative access to affected systems. The vulnerability affects a broad range of Microsoft Word versions including Word 2007, 2010, 2013, 2016, 2019, and Office 2016, making it a widespread concern for organizations that maintain legacy software environments. Organizations running affected versions of Microsoft Word are particularly vulnerable to targeted attacks, especially when users receive unsolicited documents from external sources or when document repositories lack proper security controls. The vulnerability's exploitation often requires minimal user interaction, typically just opening the malicious document, which makes it particularly effective for phishing campaigns and social engineering attacks. Security researchers have noted that this vulnerability can be chained with other exploits to create more sophisticated attack vectors, potentially bypassing modern security controls such as exploit protection mechanisms and application whitelisting policies. Organizations should implement comprehensive mitigation strategies including immediate patching of affected systems, deployment of Microsoft Office macro security controls, network monitoring for suspicious document activity, and user education regarding safe document handling practices to prevent successful exploitation of this vulnerability.