CVE-2008-0115 in Excel
Summary
by MITRE
Unspecified vulnerability in Microsoft Excel 2000 SP3 through 2007, Viewer 2003, Compatibility Pack, and Office for Mac 2004 allows user-assisted remote attackers to execute arbitrary code via malformed formulas, aka "Excel Formula Parsing Vulnerability."
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Analysis
by VulDB Data Team • 08/06/2019
The vulnerability identified as CVE-2008-0115 represents a critical security flaw in Microsoft Excel products spanning multiple versions and platforms. This issue affects Excel 2000 Service Pack 3 through Excel 2007, the Excel 2003 Viewer, the Compatibility Pack, and Office for Mac 2004, creating a wide attack surface that spans nearly a decade of Microsoft Office releases. The vulnerability falls under the category of unspecified vulnerability, indicating that while the exact technical details were not fully disclosed in the initial report, the impact was severe enough to warrant immediate attention from security professionals and organizations worldwide. The classification aligns with CWE-119 which deals with memory corruption vulnerabilities that can lead to arbitrary code execution, making this a significant concern for enterprise security teams.
The technical flaw manifests through malformed formulas within Excel spreadsheet files that trigger a buffer overflow or memory corruption during the parsing process. When Excel encounters these specially crafted formulas, the application fails to properly validate the input data structure, leading to unpredictable behavior that can be exploited by attackers. The vulnerability specifically occurs during the formula parsing phase where the software does not adequately check the boundaries of memory allocations or validate the structure of formula expressions. This parsing failure creates an opportunity for attackers to inject malicious code that executes with the privileges of the user running the vulnerable Excel application. The attack requires user interaction, meaning that a user must open the malicious spreadsheet file for the exploit to succeed, but this user-assisted nature does not diminish the severity of the vulnerability.
The operational impact of this vulnerability extends far beyond simple data corruption or application crashes. Organizations that rely heavily on Excel for business operations face significant risks when this vulnerability is exploited, as it can lead to complete system compromise. The arbitrary code execution capability allows attackers to install backdoors, steal sensitive data, or escalate privileges within the compromised system. This vulnerability particularly affects enterprise environments where users frequently exchange Excel files, making it a prime target for social engineering attacks that trick users into opening malicious spreadsheets. The attack vector through email attachments, shared network drives, or download sites means that organizations must consider both technical and human factors in their security posture. The vulnerability also impacts mobile and remote workers who may be more susceptible to phishing attacks and less controlled environments.
Mitigation strategies for CVE-2008-0115 require a multi-layered approach combining both technical and administrative controls. Microsoft released patches and updates for all affected versions of Excel, emphasizing the importance of timely patch management in preventing exploitation of known vulnerabilities. Organizations should implement strict file validation policies, including disabling macro execution and restricting the opening of files from untrusted sources. Network security controls such as email filtering and web proxy configurations can help prevent users from accessing malicious Excel files before they reach the endpoint. Security awareness training programs should educate users about the dangers of opening unexpected spreadsheet files and the importance of verifying file sources. The vulnerability's classification under ATT&CK technique T1059.005, which covers command and script interpreters, indicates that exploitation often involves the execution of malicious code through interpreted languages, further emphasizing the need for comprehensive endpoint protection measures. Regular vulnerability assessments and penetration testing can help identify systems that may still be running vulnerable versions of Excel, ensuring that all endpoints are properly secured against this and similar threats.