CVE-2025-53696

Malicious firmware execution via incomplete boot verification

Published Jul 28, 2025 · Updated Aug 19, 2025

Insufficient firmware verification in Johnson Controls iSTAR Ultra 6.9.2 and earlier allows local users to execute malicious code. The boot-time integrity check omits portions of the firmware image, so attacker-modified code in those regions passes verification. High device privileges are required directly, although a separate authenticated command-injection flaw provides a network-reachable modification path; successful tampering can persist malicious controller code.

CVSS severity9.3
Critical
EPSS probability0.10%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Insufficient firmware verification in Johnson Controls iSTAR Ultra 6.9.2 and earlier allows local users to execute malicious code. The boot-time integrity check omits portions of the firmware image, so attacker-modified code in those regions passes verification. High device privileges are required directly, although a separate authenticated command-injection flaw provides a network-reachable modification path; successful tampering can persist malicious controller code.

The record

CVE
CVE-2025-53696
Published
Jul 28, 2025
Updated
Aug 19, 2025
Vendor
Johnson Controls
Product
iSTAR Ultra
Classifications
CWE-494, CAPEC-452, CAPEC-638, T1601.001
Attack vector
local
Privileges
admin

Timeline

How it unfolded

  1. Jul 28, 2025CVE publishedPublication date reported by the CVE source.
  2. Aug 19, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <=6.9.2

What conditions does exploitation require?

Attack vectorlocal
Required privilegesadmin

What is affected?

Johnson Controls · iSTAR Ultraversion=0 <=6.9.2

Published CVSS scores

9.3DragosCVSS:4.0/AV:L/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesadmin
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-494Download of Code Without Integrity Check
CAPEC-452Infected Hardware
CAPEC-638Altered Component Firmware
T1601.001Modify System Image: System Firmware

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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