CVE-2017-2790: Justsystems Ichitaro

Critical severity, CVSS 9.8. EPSS: 1.9% chance of exploitation in the next 30 days.

When processing a record type of 0x3c from a Workbook stream from an Excel file (.xls), JustSystems Ichitaro Office trusts that the size is greater than zero, subtracts one from the length, and uses this result as the size for a memcpy. This results in a heap-based buffer overflow and can lead to code execution under the context of the application.

Affected products

• Justsystems Ichitaro: any version

Published 2017-02-24. Last modified 2026-06-17.