CVE-2007-3030 in Excel
Summary
by MITRE
Microsoft Excel 2000 SP3, 2002 SP3, 2003 SP2, and 2003 Viewer allows user-assisted remote attackers to execute arbitrary code via a malformed Excel file involving the "denoting [of] the start of a Workspace designation", which results in memory corruption, aka the "Workbook Memory Corruption Vulnerability".
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Analysis
by VulDB Data Team • 07/21/2019
The vulnerability described in CVE-2007-3030 represents a critical memory corruption flaw affecting multiple versions of Microsoft Excel software including Excel 2000 SP3, 2002 SP3, 2003 SP2, and the 2003 Viewer. This vulnerability falls under the category of buffer overflow conditions that occur during the parsing of malformed Excel files, specifically when processing Workspace designation elements within workbook files. The flaw manifests when Excel encounters a specially crafted file containing improperly formatted workspace information that triggers memory corruption during the file processing routine.
The technical mechanism behind this vulnerability involves the improper handling of Workspace designation elements within Excel's file parsing engine. When Excel attempts to parse a malformed workbook file containing crafted Workspace information, the application fails to properly validate the structure and boundaries of the workspace data. This inadequate input validation leads to memory corruption that can be exploited to execute arbitrary code with the privileges of the user running the vulnerable application. The vulnerability is classified as a user-assisted remote code execution flaw because an attacker must convince a user to open a malicious file, but once opened, the exploit can be triggered without additional user interaction.
From an operational perspective, this vulnerability presents significant risk to organizations relying on older Excel versions, particularly those that receive external files from untrusted sources or have limited patch management processes. The impact extends beyond individual user compromise to potential network-wide exploitation when users open malicious files from email attachments, shared network drives, or downloaded content. Attackers can leverage this vulnerability to install backdoors, steal sensitive data, or establish persistent access to compromised systems. The vulnerability's classification as a memory corruption issue aligns with CWE-121, which addresses stack-based buffer overflow conditions, and reflects the broader category of heap-based memory corruption issues that have been extensively documented in cybersecurity literature.
The exploitation of this vulnerability requires careful crafting of Excel files that contain malformed Workspace designation elements designed to trigger the specific parsing error. Security researchers have noted that the vulnerability affects the parsing of workspace information within Excel's internal file structures, particularly when processing complex workbook files that contain multiple sheets and workspace definitions. Organizations should consider implementing multiple layers of defense including email filtering, web application firewalls, and user education programs to prevent exploitation. The ATT&CK framework categorizes this vulnerability under the T1059.005 technique for command and scripting interpreter, as successful exploitation would typically involve executing malicious code through the compromised Excel application. Microsoft's recommended mitigation includes applying the appropriate security patches, implementing application whitelisting policies, and restricting user permissions to prevent unauthorized file execution. Organizations should also consider network segmentation and monitoring to detect potential exploitation attempts involving suspicious file access patterns or unusual network activity from Excel processes.