Cyber Resilience

CVE-2025-66602

Yokogawa Fast\/Tools r9.01 – r10.04

Published
09 February 2026
Modified
05 March 2026
Patch / advisory
CVSS Score v4 6.9
Click a component to see what it means
Raw vectorCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
EPSS Score 0.0030 23th percentile
Risk Priority 40 floored blend · peak EPSS

Summary

CVE-2025-66602 is a medium-severity Reliance on IP Address for Authentication (CWE-291) vulnerability in Yokogawa Fast\/Tools. Its CVSS base score is 6.9 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Trusted Relationship (T1199); ranked at the 23th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to IA-2 (Identification and Authentication (Organizational Users)) and IA-8 (Identification and Authentication (Non-organizational Users)) — see the control section below for these in your framework.

Deeper analysis AI-assisted summary

Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.

CVE-2025-66602 is a critical vulnerability in the FAST/TOOLS software provided by Yokogawa Electric Corporation, specifically affecting its web server component that accepts access by IP address. This flaw makes systems discoverable and exploitable by worms or scanners that randomly probe IP addresses across networks. The vulnerability impacts FAST/TOOLS packages including RVSVRN, UNSVRN, HMIWEB, FTEES, and HMIMOB in versions from R9.01 to R10.04. It has a CVSS v3.1 base score of 9.8 (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H) and is associated with CWE-291.

The attack scenario involves remote attackers with network access, including automated worms that perform random IP address searches, requiring no privileges, authentication, or user interaction. Successful exploitation can result in high-impact compromise, granting attackers full confidentiality, integrity, and availability control over the affected system.

Yokogawa has published security advisory YSAR-26-0001-E, available at https://web-material3.yokogawa.com/1/39206/files/YSAR-26-0001-E.pdf, which provides details on mitigation and patching recommendations for this vulnerability.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

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…

more

worm. The affected products and versions are as follows: FAST/TOOLS (Packages: RVSVRN, UNSVRN, HMIWEB, FTEES, HMIMOB) R9.01 to R10.04

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

T1199 Trusted Relationship Initial Access
Adversaries may breach or otherwise leverage organizations who have access to intended victims.
T1021 Remote Services Lateral Movement
Adversaries may use [Valid Accounts](https://attack.
T1133 External Remote Services Persistence
Adversaries may leverage external-facing remote services to initially access and/or persist within a network.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2025-66598Same product: Yokogawa Fast\/Tools
CVE-2025-66594Same product: Yokogawa Fast\/Tools
CVE-2025-66597Same product: Yokogawa Fast\/Tools
CVE-2025-66596Same product: Yokogawa Fast\/Tools
CVE-2025-66608Same product: Yokogawa Fast\/Tools
CVE-2025-66607Same product: Yokogawa Fast\/Tools
CVE-2025-66604Same product: Yokogawa Fast\/Tools
CVE-2025-66603Same product: Yokogawa Fast\/Tools
CVE-2025-66605Same product: Yokogawa Fast\/Tools
CVE-2025-66601Same product: Yokogawa Fast\/Tools

Affected Assets

yokogawa
fast\/tools
r9.01 — r10.04

Mitigating Controls

Mitigating Controls (NIST 800-53 r5) AI

Requires unique identification and authentication of users rather than permitting unauthenticated or spoofable attributes such as source IP.

Requires unique identification and authentication of non-organizational users, precluding reliance on IP address alone.

AC-17 Remote Access partial match

Mandates documented usage restrictions and configuration requirements for remote access that cannot be satisfied by IP-based authentication.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.AA-03 full match
prevents

Strong authentication mechanisms directly replace reliance on spoofable IP addresses.

PR.AA-01 mostly match
prevents

Managed identities and credentials supplant weak IP-based authentication decisions.

DE.CM-01 partial match
prevents

Network monitoring can detect misuse of IP authentication but does not prevent the weakness.

PR.AA-05 partial match
prevents

Authorization policies and least privilege reduce dependence on network-location assertions.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

prevents

Secure-authentication control directly addresses the weakness by requiring proper credentials instead of IP address.

prevents

Access-control policy can mandate stronger authentication than IP address alone.

prevents

Identity-management processes should replace IP-based identification with verified identities.

degrades

Authentication-information rules discourage reliance on mutable attributes such as IP addresses.

prevents

Access-rights assignment should be tied to authenticated identities, not network location.

prevents

Privileged-access rules require authenticated users rather than implicit IP trust.

References