CVE-2010-0258 in Office
Summary
by MITRE
Microsoft Office Excel 2002 SP3, 2003 SP3, and 2007 SP1 and SP2; Office 2004 and 2008 for Mac; Open XML File Format Converter for Mac; Office Excel Viewer SP1 and SP2; and Office Compatibility Pack for Word, Excel, and PowerPoint 2007 File Formats SP1 and SP2 do not properly parse the Excel file format, which allows remote attackers to execute arbitrary code via a crafted spreadsheet that causes memory to be interpreted as a different object type than intended, aka "Microsoft Office Excel Sheet Object Type Confusion Vulnerability."
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Analysis
by VulDB Data Team • 05/02/2026
The Microsoft Office Excel Sheet Object Type Confusion Vulnerability represents a critical memory corruption flaw that affects multiple versions of Microsoft Office across different platforms. This vulnerability stems from improper parsing of Excel file formats where the application fails to correctly validate object types during file processing, creating opportunities for malicious code execution through specially crafted spreadsheet files. The flaw specifically manifests when the Excel application attempts to interpret memory structures that should contain one type of object but instead contain another, leading to unpredictable behavior and potential code execution.
The technical nature of this vulnerability aligns with CWE-129, which describes improper validation of input data, and more specifically with CWE-125, which addresses out-of-bounds read conditions. The vulnerability operates through a type confusion attack pattern where an attacker crafts an Excel file containing maliciously structured data that causes the application to misinterpret memory contents. When Excel processes such files, it may attempt to access memory locations as one data type while those locations actually contain data of a different type, leading to memory corruption that can be exploited to execute arbitrary code with the privileges of the user running the application.
This vulnerability has significant operational impact across enterprise environments where Microsoft Office is widely deployed. The attack vector is particularly dangerous because it can be delivered through email attachments or web downloads, making it a common target for phishing campaigns and social engineering attacks. The vulnerability affects not only Windows-based Office installations but also Mac versions of Office, demonstrating the cross-platform nature of the flaw. Attackers can leverage this vulnerability to gain unauthorized access to systems, escalate privileges, and potentially establish persistent access within network environments.
The exploitation of this vulnerability follows patterns consistent with ATT&CK technique T1203, which involves exploiting software vulnerabilities for privilege escalation. Organizations using affected versions of Microsoft Office face substantial risk as the vulnerability allows attackers to execute code remotely without requiring user interaction beyond opening the malicious file. The impact extends beyond individual system compromise to potentially enable lateral movement within networks, as attackers can use the initial foothold to access additional systems and data resources. Security professionals should note that the vulnerability affects multiple Office versions, making comprehensive patch management essential for mitigating risk across diverse computing environments.
Mitigation strategies for this vulnerability require immediate implementation of Microsoft security patches and updates, as well as network-based protections such as email filtering and web content restrictions. Organizations should implement application whitelisting policies to prevent execution of unauthorized Office applications and consider deploying sandboxing technologies to isolate potentially malicious files. Regular security awareness training for users can help reduce the risk of successful exploitation through social engineering attacks. Additionally, monitoring network traffic for suspicious file transfers and implementing strict access controls on Office application installations can provide additional layers of defense against exploitation attempts.