Unspecified vulnerability in Microsoft Word allows user-assisted remote attackers to execute arbitrary code on Word 2000 and cause a denial of service on Word 2003 via unknown attack vectors that trigger memory corruption as exploited by Trojan.Mdropper.W and later by Trojan.Mdropper.X a different issue than CVE-2006-6456 CVE-2006-5994 and CVE-2006-6561.