IchitaroApplication · Justsystems

CVE-2017-2789

CRITICAL · 9.8 CVSS v3.0 Published 2017-02-24
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
100/100
Remediation priority · Urgent
Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
When copying filedata into a buffer, JustSystems Ichitaro Office 2016 Trial will calculate two values to determine how much data to copy from the document. If both of these values are larger than the size of the buffer, the application will choose the smaller of the two and trust it to copy data from the file. This value is larger than the buffer size, which leads to a heap-based buffer overflow. This overflow corrupts an offset in the heap used in pointer arithmetic for writing data and can lead to code execution under the context of the application.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

Heap-based buffer overflow in JustSystems Ichitaro Office 2016 Trial when copying file data. The application calculates two values to determine copy size, and when both exceed the buffer size, it incorrectly selects the smaller value which remains larger than the buffer, causing overflow that corrupts heap offsets used in pointer arithmetic and can lead to code execution.

MitigationApply vendor patch when released. Until then, restrict or disable use of Ichitaro Office 2016 Trial, implement application sandboxing, or use alternative office software to eliminate the attack vector.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
IchitaroApplication
Affected:all versions

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Confirm Ichitaro Office installation
    Open Windows Control Panel > Programs and Features, or run 'Get-ItemProperty HKLM:\Software\Microsoft\Windows\CurrentVersion\Uninstall\* | Select-Object DisplayName, DisplayVersion' in PowerShell to list installed software. Look for any JustSystems Ichitaro entry.
    Affected if JustSystems Ichitaro Office 2016 Trial appears in the installed programs list
  2. Identify exact version number
    If Ichitaro is installed, locate its executable (typically in C:\Program Files\JustSystems\Ichitaro\ or C:\Program Files (x86)\JustSystems\Ichitaro\). Right-click the main executable (e.g., ichitaro.exe) and select Properties > Details to view the File Version.
    Affected if The displayed version falls within or below the 2016 release cycle (versions prior to vendor patch availability)
  3. Determine if Trial version
    Launch Ichitaro and check the title bar or Help > About dialog for 'Trial', 'Evaluation', or '体験版' (Japanese for Trial) indicators. Alternatively, check the program folder for files named 'trial' or 'eval' in the filename.
    Affected if The installed version is identified as a Trial or Evaluation copy
  4. Verify vulnerable component exists
    Inspect the Ichitaro program directory for the file handling module responsible for copy operations. The vulnerability exists in the code that handles copying file data into buffers. No specific file name is publicly disclosed; presence of the main ichitaro.exe application indicates the vulnerable code path exists.
    Affected if The main Ichitaro application executable is present, indicating the vulnerable copy operation code is included

A user is affected if JustSystems Ichitaro Office 2016 Trial (or any unpatched Ichitaro version) is installed on the system.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

From vendor data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Apply vendor patch when released. Until then, restrict or disable use of Ichitaro Office 2016 Trial, implement application sandboxing, or use alternative office software to eliminate the attack vector.

Fix this in Ichitaro Scoped from the published advisory
  • Consultation2.0 h
  • Testing1.0 h
  • Review / QA1.0 h
4.0 hours of engineering $750
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Scan for this in your stack

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dbcve dependency scanner

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2017-2789 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data