Published:2009/04/07  Last Updated:2010/03/23

Ichitaro series buffer overflow vulnerability


The "Ichitaro" series word processing software contains a buffer overflow vulnerability.

This vulnerability is different from JVN#29211062, JVN#32981509 and JVN#50495547.

Products Affected

  • Ichitaro 2009
  • Ichitaro Government 2009
  • Ichitaro 2009 trial version
  • Ichitaro 2008
  • Ichitaro Government 2008
  • Ichitaro 2007
  • Ichitaro Government 2007
  • Ichitaro 2006
  • Ichitaro Government 2006
  • Ichitaro 2005
  • Ichitaro Bungei
  • Ichitaro 2004
  • Ichitaro 13
  • Ichitaro Viewer 2009 version and earlier


The "Ichitaro" series word processing software, from JustSystems Corporation, contains an issue in the reading of Rich Text Files resulting in a buffer overflow vulnerability. When a user opens a specially crafted file locally or through a website, arbitrary code may be executed with privleges of the user.


An attacker could execute arbitrary code with the privileges of the user.


Update the Software
Apply the update module provided by JustSystems.

Vendor Status

Vendor Status Last Update Vendor Notes
JustSystems Corporation Vulnerable 2009/04/07


  1. IPA
    Security Alert for Security Vulnerability in the Ichitaro Series

JPCERT/CC Addendum

Vulnerability Analysis by JPCERT/CC

Analyzed on 2009.04.07

Measures Conditions Severity
Access Required Routed - can be attacked over the Internet using packets
  • High
Authentication None - anonymous or no authentication (IP addresses do not count)
  • High
User Interaction Required Simple - the user must be convinced to take a standard action that does not feel harmful to most users, such as click on a link or view a file
  • Medium
Exploit Complexity Low-Medium - some expertise and/or luck required (most buffer overflows, guessing correctly in small space, expertise in Windows function calls)
  • Medium-High

Description of each analysis measures


Yuji Ukai of Fourteenforty Research Institute, Inc. reported this vulnerability to IPA.
JPCERT/CC coordinated with the developer under Information Security Early Warning Partnership.

Other Information

JPCERT Reports
CERT Advisory
CPNI Advisory
CVE CVE-2009-4737
JVN iPedia JVNDB-2009-000018

Update History