CVE-2023-23398 in Excel
Summary
by MITRE • 03/14/2023
Microsoft Excel Spoofing Vulnerability
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Analysis
by VulDB Data Team • 03/01/2025
The CVE-2023-23398 vulnerability represents a critical spoofing flaw in Microsoft Excel that allows attackers to manipulate the application's user interface to deceive users into believing they are interacting with legitimate content. This vulnerability specifically affects Excel's handling of certain file formats and rendering mechanisms, creating opportunities for malicious actors to craft deceptive spreadsheet presentations that appear authentic to unsuspecting users. The flaw resides in how Excel processes and displays certain metadata and formatting elements within spreadsheet files, potentially enabling attackers to manipulate the application's visual presentation layer.
This vulnerability operates through a sophisticated manipulation of Excel's rendering pipeline, where attackers can craft malicious files that exploit the application's trust in specific formatting patterns and metadata structures. The technical implementation involves exploiting weaknesses in how Excel validates and displays file headers, cell formatting, and visual elements that are typically considered trustworthy by end users. The flaw enables attackers to present misleading information while maintaining the appearance of legitimate spreadsheet content, making it particularly dangerous in enterprise environments where users frequently interact with spreadsheets containing sensitive data.
The operational impact of CVE-2023-23398 extends beyond simple deception, as it can facilitate more sophisticated attack vectors including credential theft, malware delivery, and social engineering campaigns. Attackers can leverage this vulnerability to create convincing phishing attempts within spreadsheet applications, where users might unknowingly interact with malicious content while believing they are working with legitimate documents. The vulnerability's exploitation can lead to unauthorized access to corporate networks, data exfiltration, and compromise of sensitive business information. Organizations using Excel extensively face significant risk as this flaw can be exploited through various attack vectors including email attachments, web downloads, and malicious file sharing scenarios.
Security professionals should implement multiple layers of defense to mitigate this vulnerability, including regular patch management, user education about suspicious spreadsheet content, and network monitoring for anomalous file access patterns. The vulnerability aligns with CWE-602, which addresses client-side input validation issues, and maps to ATT&CK technique T1566 related to spearphishing with attachments. Organizations should prioritize immediate patch deployment, implement strict file validation policies, and establish robust incident response procedures to address potential exploitation attempts. Additionally, network segmentation and email filtering solutions can provide additional protection layers against delivery mechanisms that leverage this vulnerability for initial compromise.