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PatchSiren cyber security CVE debrief

CVE-2025-43875 Johnson Controls Inc. CVE debrief

A high-severity vulnerability in Johnson Controls iSTAR access control systems could allow authenticated attackers to gain unauthorized device access. The issue affects multiple iSTAR product lines including iSTAR Ultra, iSTAR Ultra SE, iSTAR Ultra G2, iSTAR Ultra G2 SE, and iSTAR Edge G2. Johnson Controls has released patched firmware versions to address this vulnerability.

Vendor
Johnson Controls Inc.
Product
iSTAR Ultra
CVSS
HIGH 8.8
CISA KEV
Not listed in stored evidence
Original CVE published
2025-12-11
Original CVE updated
2025-12-11
Advisory published
2025-12-11
Advisory updated
2025-12-11

Who should care

Organizations using Johnson Controls iSTAR access control systems for physical security, particularly in critical infrastructure, commercial buildings, healthcare facilities, and government installations. Security teams responsible for OT/ICS environments and building automation systems should prioritize patching.

Technical summary

CVE-2025-43875 is an authentication-related vulnerability in Johnson Controls iSTAR physical access control systems. With CVSS 3.1 score 8.8 (AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H), the vulnerability allows network-based attackers with low privileges to achieve high-impact compromise of affected devices without user interaction. The vulnerability spans five product variants: iSTAR Ultra, iSTAR Ultra SE, iSTAR Ultra G2, iSTAR Ultra G2 SE, and iSTAR Edge G2. Johnson Controls has issued firmware updates and product security advisories JCI-PSA-2025-14 and JCI-PSA-2025-15 to address the issue.

Defensive priority

HIGH

Recommended defensive actions

  • Upgrade iSTAR Ultra and iSTAR Ultra SE to firmware version 6.9.7.CU01 or later
  • Upgrade iSTAR Ultra G2, iSTAR Ultra G2 SE, and iSTAR Edge G2 to firmware version 6.9.3 or later
  • Review Johnson Controls Product Security Advisories JCI-PSA-2025-14 and JCI-PSA-2025-15 for detailed mitigation guidance
  • Implement network segmentation to limit iSTAR device exposure to untrusted networks
  • Apply defense-in-depth strategies per CISA ICS recommended practices
  • Contact Johnson Controls Global Product Security for additional assistance if needed

Evidence notes

CISA published advisory ICSA-25-345-01 on 2025-12-11 with CVSS 3.1 score 8.8 (HIGH). The vulnerability requires low attack complexity and network access with low privileges, but no user interaction. Successful exploitation grants high impact across confidentiality, integrity, and availability.

Sources and references

Verified primary and authoritative sources

  • CVE-2025-43875 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2025-43875

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

  • CVE-2025-43875 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2025-43875

    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-25-345-01.json

    cisa_csaf

  • Source reference

    Unverified legacy reference

    URL: https://www.cisa.gov/news-events/ics-advisories/icsa-25-345-01

    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://www.cisa.gov/uscert/sites/default/files/publications/emailscams0905.pdf

    Reference

  • Source reference

    Unverified legacy reference

    URL: https://www.cisa.gov/uscert/ncas/tips/ST04-014

    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.