CVE-2009-3128 in Office
Summary
by MITRE
Microsoft Office Excel 2002 SP3 and 2003 SP3, and Office Excel Viewer 2003 SP3, does not properly parse the Excel file format, which allows remote attackers to execute arbitrary code via a spreadsheet with a malformed record object, aka "Excel SxView Memory Corruption Vulnerability."
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Analysis
by VulDB Data Team • 01/05/2025
The vulnerability identified as CVE-2009-3128 represents a critical memory corruption flaw within Microsoft Office Excel 2002 SP3, Excel 2003 SP3, and Excel Viewer 2003 SP3 applications. This issue stems from insufficient validation of spreadsheet file formats during the parsing process, creating a pathway for malicious actors to exploit the software through specially crafted Excel files containing malformed record objects. The vulnerability falls under the category of buffer overflow conditions that occur when the application attempts to process corrupted or malformed data structures within Excel files. According to CWE-125, this vulnerability represents an out-of-bounds read condition where the Excel application accesses memory locations beyond the intended boundaries of allocated buffers. The flaw specifically affects the SxView record parsing functionality within Excel's file format handling mechanism, which is responsible for processing various spreadsheet elements including pivot tables and data views.
The technical exploitation of this vulnerability occurs when a user opens a maliciously crafted Excel file that contains a malformed SxView record structure. The Excel application attempts to parse this corrupted record without proper bounds checking, leading to memory corruption that can be leveraged to execute arbitrary code with the privileges of the targeted user. This type of vulnerability aligns with ATT&CK technique T1203, which involves exploitation of software vulnerabilities to gain unauthorized access and execute malicious code. The memory corruption manifests as a heap-based buffer overflow when the application processes the malformed record data, potentially allowing attackers to overwrite adjacent memory locations and redirect execution flow. The vulnerability is particularly dangerous because it can be triggered through simple file opening operations, making it an ideal candidate for social engineering attacks where users might inadvertently open malicious spreadsheets through email attachments or web downloads.
The operational impact of CVE-2009-3128 extends beyond individual system compromise to potentially affect entire enterprise networks, especially in environments where Excel files are frequently shared and opened by multiple users. Organizations running affected versions of Microsoft Office are at significant risk of unauthorized code execution, data exfiltration, and potential system takeover. The vulnerability's remote exploit capability means that attackers can deliver malicious payloads through various vectors including email attachments, web-based file sharing systems, or compromised websites. Security professionals should note that this vulnerability was particularly prevalent in corporate environments where Excel files are commonly used for data analysis and reporting, making it a prime target for targeted attacks. The exploitation requires minimal user interaction beyond opening the malicious file, which increases the likelihood of successful compromise in real-world scenarios.
Mitigation strategies for CVE-2009-3128 should include immediate application of Microsoft security patches and updates, as well as implementation of network-level controls to prevent access to known malicious file sources. Organizations should deploy email filtering solutions that can identify and block suspicious Excel attachments, while also implementing application whitelisting policies to restrict execution of untrusted Office files. Network segmentation and firewall rules can help limit the spread of potential exploitation within an organization. According to industry best practices and security frameworks, regular vulnerability assessments should be conducted to identify systems running vulnerable versions of Microsoft Office, with immediate remediation prioritized for critical systems. Additionally, user education programs should emphasize the importance of verifying file sources and avoiding opening suspicious attachments. The vulnerability also highlights the importance of maintaining current security patches and following Microsoft's recommended security updates to protect against similar memory corruption vulnerabilities that may be discovered in the future.