Unspecified vulnerability, possibly a buffer overflow, in Justsystem Ichitaro 2007 and earlier allows remote attackers to execute arbitrary code via a modified document, as actively exploited in August 2007 by malware such as Tarodrop.D (Tarodrop.Q), a different vulnerability than CVE-2006-4326, CVE-2006-5424, CVE-2006-6400, and CVE-2007-1938.