Microsoft Excel 2000, 2002, 2003, Viewer 2003, Office 2004 for Mac, and Office v.X for Mac does not properly handle certain opcodes, which allows user-assisted remote attackers to execute arbitrary code via a crafted XLS file, which results in an "Improper Memory Access Vulnerability."  NOTE: an early disclosure of this issue used CVE-2006-3432, but only CVE-2007-0028 should be used.