JustSystems Ichitaro 2005 through 2011, Ichitaro Government 6, Ichitaro Government 2006 through 2010, Ichitaro Portable, Ichitaro Pro, and Ichitaro Viewer allow remote attackers to execute arbitrary code or cause a denial of service (heap memory corruption) via a crafted document, as exploited in the wild in early 2011.

Stack-based buffer overflow in JustSystems Corporation Ichitaro 13, 2004 through 2009, Viewer 2009 19.0.1.0 and earlier, and other versions allows context-dependent attackers to execute arbitrary code via a crafted Rich Text File (RTF), related to "pvpara ffooter."