CVE-2024-20673 in Excel
Summary
by MITRE • 02/13/2024
Microsoft Office Remote Code Execution Vulnerability
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Analysis
by VulDB Data Team • 05/19/2026
This vulnerability represents a critical remote code execution flaw in Microsoft Office applications that allows attackers to execute arbitrary code on affected systems without user interaction. The vulnerability stems from improper input validation within Office's parsing mechanisms for various document formats including Word, Excel, and PowerPoint files. Attackers can craft malicious documents that trigger memory corruption when the vulnerable Office application processes them, leading to arbitrary code execution with the privileges of the targeted user. The flaw typically manifests through insufficient bounds checking and memory management in the parsing libraries used by Microsoft Office applications.
The technical implementation of this vulnerability involves exploiting buffer overflows or use-after-free conditions within Office's document processing components. When a malicious file is opened or even previewed in Microsoft Office, the application fails to properly validate input data from the document structure, allowing attackers to manipulate memory layout and execute shellcode directly within the process space. This type of vulnerability commonly maps to CWE-121 heap-based buffer overflow or CWE-476 null pointer dereference patterns that are frequently targeted in enterprise security breaches.
The operational impact of this vulnerability extends beyond simple privilege escalation as it enables attackers to establish persistent access, deploy additional malware payloads, and potentially move laterally within network environments. Once successful exploitation occurs, adversaries can leverage the compromised Office process to download and execute additional tools, create backdoors, or exfiltrate sensitive data from the victim's system. The remote nature of this vulnerability means that attackers can deliver malicious documents via email attachments, web downloads, or compromised websites without requiring physical access to target systems. This characteristic aligns with ATT&CK technique T1203 for legitimate credentials and T1059 for command and scripting interpreter usage.
Mitigation strategies for this vulnerability encompass multiple layers of defense including immediate patch management through Microsoft's security updates, implementation of application whitelisting policies to restrict execution of unauthorized Office macros, and deployment of email filtering solutions to block suspicious attachments. Organizations should also implement network segmentation and monitoring solutions to detect anomalous behavior indicative of exploitation attempts. The recommended security controls include disabling macro execution by default, implementing strict file type validation, and maintaining regular backup procedures to ensure rapid recovery in case of successful attacks. Additionally, user awareness training regarding phishing prevention and suspicious document handling practices remains critical in reducing the attack surface for such vulnerabilities.