FilezenApplication · Soliton

CVE-2020-5639

CRITICAL · 9.8 CVSS v3.1 Published 2020-12-14
Fix available
A fix is available. Upgrade to after 4.2.2 or later.
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
Directory traversal vulnerability in FileZen versions from V3.0.0 to V4.2.2 allows remote attackers to upload an arbitrary file in a specific directory via unspecified vectors. As a result, an arbitrary OS command may be executed.

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

Directory traversal vulnerability in FileZen V3.0.0-V4.2.2 allows remote unauthenticated attackers to upload arbitrary files to specific directories, enabling arbitrary OS command execution. The vulnerability stems from insufficient path validation in file upload functionality, enabling attackers to escape the intended upload directory and place executable files in locations where they can be invoked.

MitigationUpgrade to FileZen version 4.2.3 or later. If immediate patching is not possible, implement network-level access controls to restrict exposure of the FileZen interface to untrusted networks.

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
FilezenApplication
Affected:>= 3.0.0, <= 4.2.2

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:3.1/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 FileZen installation
    Identify whether the Soliton FileZen application is installed on the system. Check for FileZen processes running or look for FileZen in installed programs.
    Affected if FileZen is found running or installed on the system
  2. Check installed FileZen version
    Determine the exact version of the installed FileZen application. Consult vendor documentation for version location or use system inventory tools.
    Affected if The installed version falls within the range 3.0.0 to 4.2.2 inclusive
  3. Verify file upload functionality exposure
    Determine if the FileZen web interface or file upload endpoints are accessible from the network. Check firewall rules and service binding configuration.
    Affected if FileZen file upload functionality is accessible from untrusted networks
  4. Check for suspicious uploaded files
    Inspect directories outside the expected upload base path for unexpected files, particularly executable scripts or binaries in web-accessible directories.
    Affected if Unexpected files are found in directories outside the intended upload storage area

The environment is affected if FileZen version 3.0.0 through 4.2.2 is installed and its file upload interface is network-accessible.

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.

dbcve · scoped
Upgrade available Upgrade to a release after 4.2.2
Interim mitigation

Upgrade to FileZen version 4.2.3 or later. If immediate patching is not possible, implement network-level access controls to restrict exposure of the FileZen interface to untrusted networks.

Recommended fix Moderate confidence

FileZen version 4.2.3 or later

  1. Identify the current FileZen version installed in your environment
  2. Download FileZen version 4.2.3 or later from the official vendor website (www.soliton.co.jp)
  3. Review the upgrade documentation provided by Soliton Systems
  4. Perform the upgrade following the vendor's recommended upgrade procedure
  5. After upgrading, verify the new version is installed correctly
  6. Test that the path traversal vulnerability is no longer exploitable
  7. Ensure that file upload functionality works correctly in the updated version
Caveat Review vendor release notes for any changes to configuration or functionality between your current version and the upgrade target

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Filezen Scoped from the published advisory
  • Consultation3.0 h
  • Implementation6.0 h
  • Testing4.0 h
  • Review / QA2.0 h
15.0 hours of engineering $2,640
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $4,224.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2020-5639 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

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-2020-5639 in production — separate from our analysis above.

No notes yet

Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.

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