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PatchSiren cyber security CVE debrief

CVE-2025-5241 Mitsubishi Electric Corporation CVE debrief

CVE-2025-5241 is a medium-severity availability issue in Mitsubishi Electric's MELSEC iQ-F series. A remote attacker can trigger a temporary account lockout by repeatedly submitting incorrect passwords, which can prevent legitimate access to affected controllers until the lockout expires.

Vendor
Mitsubishi Electric Corporation
Product
FX5U-32MT/ES
CVSS
MEDIUM 5.3
CISA KEV
Not listed in stored evidence
Original CVE published
2025-07-03
Original CVE updated
2025-07-03
Advisory published
2025-07-03
Advisory updated
2025-07-03

Who should care

OT/ICS operators, plant engineers, and security teams responsible for Mitsubishi Electric MELSEC iQ-F installations, especially systems exposed to remote access or connected to broader enterprise networks.

Technical summary

CISA's CSAF advisory (ICSA-25-184-04, published 2025-07-03) describes an overly restrictive account lockout mechanism affecting 73 Mitsubishi Electric MELSEC iQ-F product variants. The issue is remotely reachable and can be used to cause a denial of service by locking out a legitimate user after repeated failed login attempts. The supplied CVSS v3.1 vector is AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L (5.3).

Defensive priority

Medium; elevate if affected controllers are reachable from untrusted networks or remote-access paths.

Recommended defensive actions

  • Apply Mitsubishi Electric's stated mitigations, as no fixed version is planned in the advisory.
  • Place affected products behind a firewall or VPN when Internet access is required.
  • Use the devices within a LAN and block access from untrusted networks and hosts.
  • Restrict physical access to the affected products and the LAN connected to them.
  • Enable and use the IP filter function to block access from untrusted hosts, following the relevant Mitsubishi Electric manuals.
  • Review Mitsubishi Electric's security bulletin and operator manuals for the affected model family before making network or access changes.

Evidence notes

All core facts are taken from the CISA CSAF advisory for ICSA-25-184-04, published and modified on 2025-07-03. The advisory states that the issue is a DoS caused by an overly restrictive account lockout mechanism, affects 73 product variants in the MELSEC iQ-F family, and has no planned fixed version. The supplied CVSS v3.1 score/vector are 5.3 and AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L.

Sources and references

Verified primary and authoritative sources

  • CVE-2025-5241 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2025-5241

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2025-5241 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2025-5241

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

  • Source item URL

    Unverified legacy reference

    URL: https://raw.githubusercontent.com/cisagov/CSAF/develop/csaf_files/OT/white/2025/icsa-25-184-04.json

    cisa_csaf

  • Source reference

    Unverified legacy reference

    URL: https://www.cisa.gov/news-events/ics-advisories/icsa-25-184-04

    Reference

  • Source reference

    Unverified legacy reference

    URL: https://www.cisa.gov/uscert/ics/alerts/ICS-ALERT-10-301-01

    Reference

  • Source reference

    Unverified legacy reference

    URL: https://www.cisa.gov/resources-tools/resources/ics-recommended-practices

    Reference

  • Source reference

    Unverified legacy reference

    URL: https://www.cisa.gov/sites/default/files/publications/Cybersecurity_Best_Practices_for_Industrial_Control_Systems.pdf

    Reference

  • Source reference

    Unverified legacy reference

    URL: https://www.cisa.gov/topics/industrial-control-systems

    Reference

  • Source reference

    Unverified legacy reference

    URL: https://us-cert.cisa.gov/sites/default/files/recommended_practices/NCCIC_ICS-CERT_Defense_in_Depth_2016_S508C.pdf

    Reference

  • Source reference

    Unverified legacy reference

    URL: https://www.cisa.gov/uscert/ics/tips/ICS-TIP-12-146-01B

    Reference

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.