Microsoft Office Excel 2007 SP1 and SP2; Office 2008 for Mac; Open XML File Format Converter for Mac; Office Excel Viewer SP1 and SP2; Office Compatibility Pack for Word, Excel, and PowerPoint 2007 File Formats SP1 and SP2; and Office SharePoint Server 2007 SP1 and SP2 do not validate ZIP headers during decompression of Open XML (.XLSX) documents, which allows remote attackers to execute arbitrary code via a crafted document that triggers access to uninitialized memory locations, aka "Microsoft Office Excel XLSX File Parsing Code Execution Vulnerability."
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A8407
https://docs.microsoft.com/en-us/security-updates/securitybulletins/2010/ms10-017
http://www.zerodayinitiative.com/advisories/ZDI-10-025/
http://www.us-cert.gov/cas/techalerts/TA10-068A.html
http://www.securitytracker.com/id?1023698
http://www.securityfocus.com/archive/1/509979/100/0/threaded