CVE-2008-0114 in Excel
Summary
by MITRE
Unspecified vulnerability in Microsoft Excel 2000 SP3 through 2003 SP2, Viewer 2003, and Office for Mac 2004 allows user-assisted remote attackers to execute arbitrary code via crafted Style records that trigger memory corruption.
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Analysis
by VulDB Data Team • 08/06/2019
This vulnerability resides within Microsoft Excel 2000 Service Pack 3 through Excel 2003 Service Pack 2, as well as the 2003 Viewer and Office for Mac 2004 applications. The flaw manifests in the handling of Style records within Excel files, specifically when these records contain malformed or crafted data that triggers memory corruption conditions. The vulnerability operates under the Common Weakness Enumeration category CWE-125, which describes out-of-bounds read conditions that can lead to memory corruption and arbitrary code execution. This represents a classic buffer overflow scenario where the application fails to properly validate the boundaries of memory allocations when processing structured data elements.
The technical implementation of this vulnerability exploits the way Excel parses and processes Style records within spreadsheet files. When a maliciously crafted Excel file containing specially constructed Style records is opened, the application's parsing routine fails to properly validate the length or content of these records. This validation failure results in memory corruption that can be leveraged by attackers to execute arbitrary code with the privileges of the user running the application. The user-assisted nature of this attack means that a user must intentionally open the malicious file, but the execution occurs without requiring any additional interaction from the user once the file is opened. This attack pattern aligns with the MITRE ATT&CK framework under the technique T1059.005 for command and scripting interpreter, specifically targeting the execution of malicious code through application-level vulnerabilities.
The operational impact of this vulnerability extends beyond simple code execution, as it represents a critical security flaw that can be exploited in phishing campaigns or targeted attacks against organizations. Attackers can craft malicious Excel files that appear legitimate but contain the malicious Style records designed to trigger the memory corruption. Once executed, the compromised system could allow attackers to install additional malware, steal sensitive data, or establish persistence within the network. The vulnerability affects multiple versions of Microsoft Office, making it particularly dangerous as organizations with legacy systems or those slow to patch could remain exposed. Organizations relying on Excel for data processing and analysis face significant risk, as the attack vector is through seemingly innocuous spreadsheet files that users routinely open.
Mitigation strategies should include immediate patching of affected Microsoft Office versions to address the underlying memory corruption issue. Microsoft released security updates that fixed the Style record parsing routine to properly validate input data and prevent memory corruption conditions. Organizations should also implement strict file validation policies, particularly for files received from external sources or untrusted networks. Network-based security controls such as email filtering and web application firewalls can help prevent the delivery of malicious Excel files to end users. Additionally, user education regarding the dangers of opening unexpected spreadsheet files and implementing least privilege principles can significantly reduce the potential impact of exploitation. The vulnerability demonstrates the importance of proper input validation and memory safety practices in office productivity software, aligning with security best practices outlined in the OWASP Top Ten and other industry security frameworks. Regular security assessments and vulnerability scanning should be conducted to identify any remaining instances of affected software versions within the organization.