wksss.exe 8.4.702.0 in Microsoft Works Spreadsheet 8.0 allows remote attackers to cause a denial of service (CPU consumption or crash) via crafted (1) Works, (2) Excel, and (3) Lotus 1-2-3 files.
http://www.vupen.com/english/advisories/2006/2813
http://www.securityfocus.com/archive/1/440056/100/0/threaded