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".
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A1709
https://exchange.xforce.ibmcloud.com/vulnerabilities/35217
https://docs.microsoft.com/en-us/security-updates/securitybulletins/2007/ms07-036
http://www.vupen.com/english/advisories/2007/2478
http://www.us-cert.gov/cas/techalerts/TA07-191A.html
http://www.securitytracker.com/id?1018352
http://www.securityfocus.com/bid/24803
http://secunia.com/advisories/25995
http://archive.cert.uni-stuttgart.de/bugtraq/2007/07/msg00254.html