Fast\/toolsApplication · Yokogawa

CVE-2025-66602

CRITICAL · 9.8 CVSS v3.1 Published 2026-02-09
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
A vulnerability has been found in FAST/TOOLS provided by Yokogawa Electric Corporation. The web server accepts access by IP address. When a worm that randomly searches for IP addresses intrudes into the network, it could potentially be attacked by the worm. The affected products and versions are as follows: FAST/TOOLS (Packages: RVSVRN, UNSVRN, HMIWEB, FTEES, HMIMOB) R9.01 to R10.04

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 · moderate confidence

The FAST/TOOLS web server accepts connections based solely on IP address without additional authentication or access control verification. When exposed to network segments accessible by worms scanning random IP addresses, the server can be directly attacked.

MitigationImplement proper authentication mechanisms and network segmentation to restrict web server access. Apply firewall rules to limit exposure to trusted IPs only, and upgrade to patched versions when available.

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
Fast\/toolsApplication
Affected:>= r9.01, <= r10.04

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. Identify if Yokogawa Fast/TOOLS is installed
    Check for Fast/TOOLS software components or services on the system. Look for processes named 'FAST/TOOLS', 'FastTools', or related web server processes. Consult system inventory or installed software lists.
    Affected if Fast/TOOLS software is found on the system
  2. Determine the installed Fast/TOOLS version
    Use system administration tools, check installed program version information, or look for version details in Fast/TOOLS documentation or configuration files. Compare the version against the affected range: r9.01 through r10.04.
    Affected if Installed version falls within r9.01 to r10.04 inclusive
  3. Verify if the Fast/TOOLS web server is network-accessible
    Check network configuration, firewall rules, and listening ports (typically HTTP/HTTPS ports used by Fast/TOOLS web interface). Determine if the web server bind address allows connections from untrusted network segments.
    Affected if Web server accepts connections from network segments accessible to untrusted or random IP addresses
  4. Confirm whether IP-based authentication is the sole access control
    Review Fast/TOOLS web server configuration and authentication settings. Determine if access is granted purely based on source IP address without additional username/password, token, or multi-factor authentication.
    Affected if IP address is the only authentication mechanism enforced for web server access

The environment is affected if Fast/TOOLS version r9.01 through r10.04 is installed and the web server is accessible from untrusted network segments with IP-based authentication as the sole access control.

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

Implement proper authentication mechanisms and network segmentation to restrict web server access. Apply firewall rules to limit exposure to trusted IPs only, and upgrade to patched versions when available.

Fix this in Fast\/tools Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing6.0 h
  • Review / QA2.0 h
20.0 hours of engineering $3,500
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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-2025-66602 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
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