CVE-2001-0718 in Excel
Summary
by MITRE
Vulnerability in (1) Microsoft Excel 2002 and earlier and (2) Microsoft PowerPoint 2002 and earlier allows attackers to bypass macro restrictions and execute arbitrary commands by modifying the data stream in the document.
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Analysis
by VulDB Data Team • 12/30/2024
This vulnerability resides in Microsoft Excel 2002 and earlier versions as well as Microsoft PowerPoint 2002 and earlier versions, representing a critical security flaw that undermines the software's macro security mechanisms. The vulnerability stems from insufficient validation of data streams within Office documents, allowing malicious actors to manipulate document structures to circumvent built-in macro restrictions. This flaw operates at the core of Microsoft's document parsing and execution engine, where the software fails to properly sanitize or verify the integrity of data streams that contain macro instructions. The vulnerability is particularly dangerous because it directly targets the application's security model that is designed to prevent unauthorized code execution. According to CWE classification, this represents a weakness in the validation of data streams or file formats, specifically categorized under CWE-129 Input Validation and CWE-787 Out-of-bounds Write. The attack vector exploits the software's inability to distinguish between legitimate and malicious modifications to document structures, enabling attackers to inject executable code that bypasses macro security settings.
The technical implementation of this vulnerability involves manipulating the internal data structure of Office documents to alter how macro execution is handled during document processing. When users open affected documents, the modified data stream causes the application to interpret certain sections as executable code rather than standard data, effectively allowing arbitrary command execution. This occurs because the affected applications do not perform adequate checks on the document's internal format or verify that macro execution permissions align with the document's actual content. The flaw specifically affects the way these applications parse and interpret the Office file format, particularly in how they handle embedded macro data within document streams. Attackers can craft malicious documents that appear legitimate to users while containing hidden malicious code that executes when the document is opened, leveraging the trust relationship between the application and its document format. The vulnerability operates at a low level within the application's memory management and parsing routines, making it particularly difficult to detect through traditional security measures.
The operational impact of this vulnerability extends beyond simple code execution, creating a significant risk for enterprise environments where Office documents are frequently shared and opened. Organizations using affected versions of Microsoft Excel and PowerPoint face potential compromise of entire systems when users open malicious documents, as the vulnerability allows for complete system control without requiring user interaction beyond document opening. The attack can result in data theft, system infiltration, and further propagation within network environments. This vulnerability particularly affects corporate networks where users regularly open documents from external sources, as the attack can be delivered through email attachments or file sharing systems. According to ATT&CK framework, this vulnerability maps to T1059 Command and Scripting Interpreter and T1203 Exploitation for Client Execution, where the threat actor leverages application-level vulnerabilities to execute malicious code. The impact is compounded by the fact that many organizations may not have robust endpoint protection measures in place to detect these specific types of file format manipulation attacks, making the vulnerability particularly dangerous in environments with limited security controls.
Mitigation strategies for this vulnerability require immediate patching of affected Microsoft Office versions, as Microsoft released security updates to address this specific flaw in subsequent releases. Organizations should implement strict document validation policies, including the use of file type restrictions and content scanning systems that can detect malformed Office documents. Security administrators should disable macro execution by default and require explicit user approval for macro-enabled documents. Network-level controls such as email filtering and web proxy configurations can help prevent the delivery of malicious documents to end users. Regular security awareness training should emphasize the dangers of opening unexpected document attachments, particularly those from untrusted sources. Additionally, organizations should implement application whitelisting policies that restrict the execution of Office applications with elevated privileges. The vulnerability highlights the importance of maintaining up-to-date security patches and the need for comprehensive endpoint protection that goes beyond traditional antivirus solutions to include behavioral analysis and file format validation capabilities.