CVE-2024-21379 in Office
Summary
by MITRE • 02/13/2024
Microsoft Word Remote Code Execution Vulnerability
If you want to get best quality of vulnerability data, you may have to visit VulDB.
Analysis
by VulDB Data Team • 05/25/2026
This vulnerability represents a critical remote code execution flaw in Microsoft Word that allows attackers to execute arbitrary code on affected systems when users open maliciously crafted Word documents. The vulnerability stems from improper input validation within Word's document parsing engine, specifically in how the application handles certain file format structures and embedded objects. Attackers can craft malicious documents that exploit this weakness through carefully constructed Office Open XML elements or legacy binary formats, leading to unauthorized code execution with the privileges of the logged-on user. The flaw exists at the application layer where Word fails to properly sanitize user-supplied data during document processing, creating a pathway for malicious payloads to be interpreted and executed without proper validation mechanisms. This vulnerability directly maps to CWE-121, which describes stack-based buffer overflow conditions, and CWE-787, representing out-of-bounds write vulnerabilities that can lead to arbitrary code execution. The attack surface is extensive since Word is widely used across enterprise environments and personal systems, making successful exploitation potentially devastating. The operational impact includes complete system compromise, data exfiltration, persistence mechanisms establishment, and lateral movement capabilities for attackers. Additionally, the vulnerability can be exploited through various attack vectors including email attachments, web downloads, and malicious Office documents served through compromised websites. The exploitation process typically involves crafting a document with malicious embedded content that triggers the vulnerable parsing code path when the document is opened, often requiring no user interaction beyond the initial document opening. This vulnerability aligns with ATT&CK technique T1204.002 for legitimate user execution and T1059 for command and scripting interpreter usage. The threat landscape is particularly concerning because Word documents are commonly shared in business environments and personal communications, making social engineering attacks highly effective. Organizations should implement multiple layers of defense including email filtering, application control policies, and regular security updates to mitigate this risk effectively. The vulnerability also highlights the importance of zero-trust security models where document processing is isolated and validated before execution. Microsoft has addressed this through security patches that improve input validation and memory management within Word's document parsing components, requiring immediate deployment across all affected systems to prevent exploitation.