CVE-2006-1302 in Excel
Summary
by MITRE
Buffer overflow in Microsoft Excel 2000 through 2003 allows user-assisted attackers to execute arbitrary code via a .xls file with certain crafted fields in a SELECTION record, which triggers memory corruption, aka "Malformed SELECTION record Vulnerability."
If you want to get best quality of vulnerability data, you may have to visit VulDB.
Analysis
by VulDB Data Team • 05/04/2019
The CVE-2006-1302 vulnerability represents a critical buffer overflow flaw in Microsoft Excel versions 2000 through 2003 that enables remote code execution through maliciously crafted spreadsheet files. This vulnerability specifically targets the SELECTION record within Excel's file format parsing mechanism, demonstrating how seemingly benign spreadsheet elements can become vector for sophisticated attacks. The flaw exists in the way Excel handles the parsing of selection records within .xls files, where insufficient bounds checking allows attackers to craft malicious records that exceed allocated memory buffers. This vulnerability falls under CWE-121, which describes stack-based buffer overflow conditions, and aligns with ATT&CK technique T1059.005 for command and scripting interpreter execution through malicious document manipulation.
The technical exploitation of this vulnerability occurs when a user opens a specially crafted .xls file containing a malformed SELECTION record that contains more data than the allocated buffer space. When Excel attempts to process this record, the excessive data overflows into adjacent memory locations, potentially corrupting critical program structures including return addresses on the stack. This memory corruption can be manipulated by attackers to redirect execution flow to malicious code placed within the overflowed buffer, effectively allowing arbitrary code execution with the privileges of the victim user. The vulnerability is particularly dangerous because it requires user interaction through opening a malicious file, making it a classic example of a user-assisted attack vector that leverages social engineering elements.
The operational impact of CVE-2006-1302 extends beyond simple code execution to encompass potential system compromise and data exfiltration capabilities. Attackers exploiting this vulnerability can gain full control over affected systems, potentially leading to persistent backdoors, credential harvesting, and lateral movement within network environments. The widespread adoption of Microsoft Excel 2000 through 2003 in enterprise environments made this vulnerability particularly dangerous as it affected millions of potential targets. Organizations running these older Excel versions faced significant risk exposure, as the vulnerability could be exploited through various attack vectors including email attachments, web downloads, and removable media. The attack surface was further expanded by the fact that many users would automatically open spreadsheet files without considering their source legitimacy.
Mitigation strategies for CVE-2006-1302 primarily focus on immediate patching and operational security measures. Microsoft released security updates that addressed the buffer overflow in Excel's file parsing mechanism, specifically targeting the SELECTION record handling code. Organizations should implement strict file validation policies, including content filtering for spreadsheet files, and disable automatic execution of macros in Excel environments. Network security controls such as email filtering and web proxy restrictions can prevent malicious .xls files from reaching end users. Additionally, regular security awareness training for employees helps reduce the risk of social engineering attacks that exploit this vulnerability. The remediation process should include comprehensive testing of patches in controlled environments before deployment to ensure compatibility with existing business applications and workflows.