CVE-2013-3644: Unspecified vulnerability in JustSystems Ichitaro 2006 through 2013; Ichitaro Pro through 2; Ichitaro Governme

This month

HIGH 10.0DOWNGRADEMITIGATEMITIGATE

CVE-2013-3644 is a high-severity flaw (CVSS 10.0) affecting ichitaro, ichitaro just school, ichitaro portable. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Unspecified vulnerability in JustSystems Ichitaro 2006 through 2013; Ichitaro Pro through 2; Ichitaro Government 6, 7, and 2006 through 2010; Ichitaro Portable with oreplug; Ichitaro Viewer; and Ichitaro JUST School through 2010 allows remote attackers to execute arbitrary code via a crafted document.

Why this priority

Critical severity
EPSS top 9%: very likely to be exploited

No fix is published yet: follow the downgrade or mitigation steps.

Risk facts

CVSS score	10.0 (High)
EPSS exploit chance	4.2% (top 9%)
CISA exploited list	No
Published	2013-06-18
Last modified	2026-06-16

Publisher (CNA): JPCERT/CC · Vendor: justsystems

Last updated 2026-06-16 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2013-06-18 18:55 UTCPublished CVE record published
2026-06-16 23:55 UTCUpdated Record last modified

justsystems ichitaro DOWNGRADE

Affected: 6 · 7 · 2006 · 2007 · 2008 · 2009 · 2010 · 2011

Fixed in: no fixed release known

Safe to downgrade to: a release before 6

1. Check installed version

apt-cache policy ichitaro || rpm -q ichitaro || ichitaro --version

2. No fixed release: DOWNGRADE to a release before 6 (Debian / Ubuntu)

apt-cache madison ichitaro sudo apt install ichitaro=<VERSION_BEFORE_6> sudo apt-mark hold ichitaro

2. No fixed release: DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list ichitaro sudo dnf downgrade ichitaro-<VERSION_BEFORE_6> sudo dnf versionlock add ichitaro

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

justsystems ichitaro just school MITIGATE

Affected: all versions

Fixed in: no fixed release known

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy ichitaro-just-school || rpm -q ichitaro-just-school || ichitaro-just-school --version

No fixed or unaffected release known

Apply the vendor mitigation from the advisory, disable the affected feature, or restrict network access.

justsystems ichitaro portable MITIGATE

Affected: all versions

Fixed in: no fixed release known

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy ichitaro-portable || rpm -q ichitaro-portable || ichitaro-portable --version

No fixed or unaffected release known

Apply the vendor mitigation from the advisory, disable the affected feature, or restrict network access.

justsystems ichitaro viewer MITIGATE

Affected: all versions

Fixed in: no fixed release known

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy ichitaro-viewer || rpm -q ichitaro-viewer || ichitaro-viewer --version

No fixed or unaffected release known

Apply the vendor mitigation from the advisory, disable the affected feature, or restrict network access.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2013-3644?

ichitaro: downgrade or apply the listed mitigation; ichitaro just school: mitigate or apply the listed mitigation; ichitaro portable: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2013-3644 being exploited?

CVE-2013-3644 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2013-3644 affect?

CVE-2013-3644 affects ichitaro, ichitaro just school, ichitaro portable. Severity is high (CVSS 10.0). Unspecified vulnerability in JustSystems Ichitaro 2006 through 2013; Ichitaro Pro through 2; Ichitaro Government 6, 7, and 2006 through 2010; Ichitaro Portable with oreplug; Ichitaro Viewer; and Ichitaro JUST School through 2010 allows remo

How urgent is CVE-2013-3644?

Priority 58/100. Critical severity; EPSS top 9%: very likely to be exploited

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References

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