CVE-2009-3133 in Office
Summary
by MITRE
Microsoft Office Excel 2002 SP3, Office 2004 and 2008 for Mac, and Open XML File Format Converter for Mac allow remote attackers to execute arbitrary code via a spreadsheet containing a malformed object that triggers memory corruption, related to "loading Excel records," aka "Excel Document Parsing Memory Corruption Vulnerability."
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Analysis
by VulDB Data Team • 01/05/2025
The vulnerability identified as CVE-2009-3133 represents a critical memory corruption flaw affecting Microsoft Office Excel 2002 SP3, Office 2004 and 2008 for Mac, and the Open XML File Format Converter for Mac. This issue stems from improper handling of Excel records during the document parsing process, creating a condition where maliciously crafted spreadsheet files can trigger unauthorized code execution. The vulnerability specifically manifests when the affected software attempts to load and process malformed objects within Excel files, leading to memory corruption that adversaries can exploit to gain arbitrary code execution privileges on target systems.
From a technical perspective, this vulnerability falls under the CWE-125 vulnerability type, which describes out-of-bounds read conditions that can result in memory corruption and potential code execution. The flaw occurs during the parsing of Excel records where the application fails to properly validate or sanitize input data from spreadsheet files. When processing malformed objects within Excel documents, the software's memory management mechanisms become compromised, creating opportunities for attackers to manipulate memory contents and execute malicious code. The vulnerability is particularly dangerous because it operates at the parsing layer of the application, meaning that simply opening a malicious file can trigger the exploit without requiring any additional user interaction beyond the standard document opening process.
The operational impact of CVE-2009-3133 extends beyond simple code execution to encompass broader security implications for enterprise environments. Attackers can leverage this vulnerability to deploy malware, establish backdoors, or escalate privileges within compromised systems. The vulnerability affects multiple versions of Microsoft Office across different platforms, making it particularly attractive to threat actors seeking maximum impact. Organizations using these affected software versions face significant risk of unauthorized access, data breaches, and potential lateral movement within their networks. The exploit requires minimal user interaction beyond opening the malicious file, making it highly effective for phishing campaigns and social engineering attacks. This vulnerability also aligns with ATT&CK technique T1059.005, which covers the execution of malicious code through Microsoft Office applications, and T1203, which involves the exploitation of software vulnerabilities for privilege escalation.
Mitigation strategies for CVE-2009-3133 should prioritize immediate software updates and patches from Microsoft, as the vendor has released security updates addressing this specific vulnerability. Organizations should implement strict file validation policies, particularly for spreadsheet files received from external sources or untrusted entities. Network-based protections such as email filtering systems should be configured to block potentially malicious Office documents, while endpoint protection solutions should be enhanced to detect and prevent exploitation attempts. System administrators should consider implementing application whitelisting policies to restrict execution of unauthorized Office applications and disable unnecessary features that could contribute to exploitation. Regular security assessments and vulnerability scanning should be conducted to identify any remaining instances of affected software versions within the organization's infrastructure. Additionally, user education programs should emphasize the importance of not opening suspicious spreadsheet files and maintaining awareness of social engineering tactics that might exploit this vulnerability. The remediation process should also include monitoring network traffic for indicators of exploitation attempts and implementing proper incident response procedures to quickly address any successful exploitation attempts.