ICSA-26-069-03
Vulnerability from csaf_cisa - Published: 2026-03-10 06:00 - Updated: 2026-03-26 06:00Summary
Honeywell IQ4 Series BMS Controller (Update A)
Notes
Legal Notice and Terms of Use: This product is provided subject to this Notification (https://www.cisa.gov/notification) and this Privacy & Use policy (https://www.cisa.gov/privacy-policy).
Risk evaluation: Successful exploitation of this vulnerability could allow an unauthorized attacker to access controller management settings, control components, disclose information, or cause a denial-of-service condition.
Critical infrastructure sectors: Commercial Facilities, Critical Manufacturing, Government Services and Facilities, Healthcare and Public Health
Countries/areas deployed: Worldwide
Company headquarters location: United States
Recommended Practices: CISA recommends users take defensive measures to minimize the risk of exploitation of this vulnerability.
Recommended Practices: Minimize network exposure for all control system devices and/or systems, ensuring they are not accessible from the internet.
Recommended Practices: Locate control system networks and remote devices behind firewalls and isolating them from business networks.
Recommended Practices: When remote access is required, use more secure methods, such as Virtual Private Networks (VPNs), recognizing VPNs may have vulnerabilities and should be updated to the most current version available. Also recognize VPN is only as secure as the connected devices.
Recommended Practices: CISA reminds organizations to perform proper impact analysis and risk assessment prior to deploying defensive measures.
Recommended Practices: CISA also provides a section for control systems security recommended practices on the ICS webpage on cisa.gov/ics. Several CISA products detailing cyber defense best practices are available for reading and download, including Improving Industrial Control Systems Cybersecurity with Defense-in-Depth Strategies.
Recommended Practices: CISA encourages organizations to implement recommended cybersecurity strategies for proactive defense of ICS assets.
Recommended Practices: Additional mitigation guidance and recommended practices are publicly available on the ICS webpage at cisa.gov/ics in the technical information paper, ICS-TIP-12-146-01B--Targeted Cyber Intrusion Detection and Mitigation Strategies.
Recommended Practices: Organizations observing suspected malicious activity should follow established internal procedures and report findings to CISA for tracking and correlation against other incidents.
Recommended Practices: CISA also recommends users take the following measures to protect themselves from social engineering attacks:
Recommended Practices: Do not click web links or open attachments in unsolicited email messages.
Recommended Practices: Refer to Recognizing and Avoiding Email Scams for more information on avoiding email scams.
Recommended Practices: Refer to Avoiding Social Engineering and Phishing Attacks for more information on social engineering attacks.
Recommended Practices: No known public exploitation specifically targeting this vulnerability has been reported to CISA at this time.
9.8 (Critical)
Affected products
Known affected
5 products
| Product | Identifier | Version | Remediation |
|---|---|---|---|
|
Honeywell IQ4E Firmware: <v3.30
Honeywell / IQ4E Firmware
|
<v3.30 |
Mitigation
Mitigation
Mitigation
Mitigation
Mitigation
Mitigation
Mitigation
Mitigation
Mitigation
Mitigation
fix
Mitigation
fix
|
|
|
Honeywell IQ412 Firmware: <v3.30
Honeywell / IQ412 Firmware
|
<v3.30 |
Mitigation
Mitigation
Mitigation
Mitigation
Mitigation
Mitigation
Mitigation
Mitigation
Mitigation
Mitigation
fix
Mitigation
fix
|
|
|
Honeywell IQ422 Firmware: <v3.30
Honeywell / IQ422 Firmware
|
<v3.30 |
Mitigation
Mitigation
Mitigation
Mitigation
Mitigation
Mitigation
Mitigation
Mitigation
Mitigation
Mitigation
fix
Mitigation
fix
|
|
|
Honeywell IQ4NC Firmware: <v3.30
Honeywell / IQ4NC Firmware
|
<v3.30 |
Mitigation
Mitigation
Mitigation
Mitigation
Mitigation
Mitigation
Mitigation
Mitigation
Mitigation
Mitigation
fix
Mitigation
fix
|
|
|
Honeywell IQ41x Firmware: <v3.30
Honeywell / IQ41x Firmware
|
<v3.30 |
Mitigation
Mitigation
Mitigation
Mitigation
Mitigation
Mitigation
Mitigation
Mitigation
Mitigation
Mitigation
fix
Mitigation
fix
|
References
17 references
{
"document": {
"acknowledgments": [
{
"names": [
"Gjoko Krstic"
],
"organization": "Zero Science",
"summary": "reported this vulnerability to Honeywell"
}
],
"category": "csaf_security_advisory",
"csaf_version": "2.0",
"distribution": {
"text": "Disclosure is not limited",
"tlp": {
"label": "WHITE",
"url": "https://www.cisa.gov/news-events/news/traffic-light-protocol-tlp-definitions-and-usage"
}
},
"lang": "en-US",
"notes": [
{
"category": "legal_disclaimer",
"text": "This product is provided subject to this Notification (https://www.cisa.gov/notification) and this Privacy \u0026 Use policy (https://www.cisa.gov/privacy-policy).",
"title": "Legal Notice and Terms of Use"
},
{
"category": "summary",
"text": "Successful exploitation of this vulnerability could allow an unauthorized attacker to access controller management settings, control components, disclose information, or cause a denial-of-service condition.",
"title": "Risk evaluation"
},
{
"category": "other",
"text": "Commercial Facilities, Critical Manufacturing, Government Services and Facilities, Healthcare and Public Health",
"title": "Critical infrastructure sectors"
},
{
"category": "other",
"text": "Worldwide",
"title": "Countries/areas deployed"
},
{
"category": "other",
"text": "United States",
"title": "Company headquarters location"
},
{
"category": "general",
"text": "CISA recommends users take defensive measures to minimize the risk of exploitation of this vulnerability.",
"title": "Recommended Practices"
},
{
"category": "general",
"text": "Minimize network exposure for all control system devices and/or systems, ensuring they are not accessible from the internet.",
"title": "Recommended Practices"
},
{
"category": "general",
"text": "Locate control system networks and remote devices behind firewalls and isolating them from business networks.",
"title": "Recommended Practices"
},
{
"category": "general",
"text": "When remote access is required, use more secure methods, such as Virtual Private Networks (VPNs), recognizing VPNs may have vulnerabilities and should be updated to the most current version available. Also recognize VPN is only as secure as the connected devices.",
"title": "Recommended Practices"
},
{
"category": "general",
"text": "CISA reminds organizations to perform proper impact analysis and risk assessment prior to deploying defensive measures.",
"title": "Recommended Practices"
},
{
"category": "general",
"text": "CISA also provides a section for control systems security recommended practices on the ICS webpage on cisa.gov/ics. Several CISA products detailing cyber defense best practices are available for reading and download, including Improving Industrial Control Systems Cybersecurity with Defense-in-Depth Strategies.",
"title": "Recommended Practices"
},
{
"category": "general",
"text": "CISA encourages organizations to implement recommended cybersecurity strategies for proactive defense of ICS assets.",
"title": "Recommended Practices"
},
{
"category": "general",
"text": "Additional mitigation guidance and recommended practices are publicly available on the ICS webpage at cisa.gov/ics in the technical information paper, ICS-TIP-12-146-01B--Targeted Cyber Intrusion Detection and Mitigation Strategies.",
"title": "Recommended Practices"
},
{
"category": "general",
"text": "Organizations observing suspected malicious activity should follow established internal procedures and report findings to CISA for tracking and correlation against other incidents.",
"title": "Recommended Practices"
},
{
"category": "general",
"text": "CISA also recommends users take the following measures to protect themselves from social engineering attacks:",
"title": "Recommended Practices"
},
{
"category": "general",
"text": "Do not click web links or open attachments in unsolicited email messages.",
"title": "Recommended Practices"
},
{
"category": "general",
"text": "Refer to Recognizing and Avoiding Email Scams for more information on avoiding email scams.",
"title": "Recommended Practices"
},
{
"category": "general",
"text": "Refer to Avoiding Social Engineering and Phishing Attacks for more information on social engineering attacks.",
"title": "Recommended Practices"
},
{
"category": "general",
"text": "No known public exploitation specifically targeting this vulnerability has been reported to CISA at this time.",
"title": "Recommended Practices"
}
],
"publisher": {
"category": "coordinator",
"contact_details": "central@cisa.dhs.gov",
"name": "CISA",
"namespace": "https://www.cisa.gov/"
},
"references": [
{
"category": "self",
"summary": "ICS Advisory ICSA-26-069-03 JSON",
"url": "https://raw.githubusercontent.com/cisagov/CSAF/develop/csaf_files/OT/white/2026/icsa-26-069-03.json"
},
{
"category": "self",
"summary": "ICSA Advisory ICSA-26-069-03 - Web Version",
"url": "https://www.cisa.gov/news-events/ics-advisories/icsa-26-069-03"
},
{
"category": "external",
"summary": "Recommended Practices",
"url": "https://www.cisa.gov/uscert/ics/alerts/ICS-ALERT-10-301-01"
},
{
"category": "external",
"summary": "Recommended Practices",
"url": "https://www.cisa.gov/resources-tools/resources/ics-recommended-practices"
},
{
"category": "external",
"summary": "Recommended Practices",
"url": "https://www.cisa.gov/sites/default/files/publications/Cybersecurity_Best_Practices_for_Industrial_Control_Systems.pdf"
},
{
"category": "external",
"summary": "Recommended Practices",
"url": "https://www.cisa.gov/topics/industrial-control-systems"
},
{
"category": "external",
"summary": "Recommended Practices",
"url": "https://www.cisa.gov/uscert/sites/default/files/publications/emailscams0905.pdf"
},
{
"category": "external",
"summary": "Recommended Practices",
"url": "https://www.cisa.gov/uscert/ncas/tips/ST04-014"
},
{
"category": "external",
"summary": "Recommended Practices",
"url": "https://www.cisa.gov/news-events/ics-alerts/ics-alert-10-301-01"
},
{
"category": "external",
"summary": "Recommended Practices",
"url": "https://www.cisa.gov/sites/default/files/recommended_practices/NCCIC_ICS-CERT_Defense_in_Depth_2016_S508C.pdf"
},
{
"category": "external",
"summary": "Recommended Practices",
"url": "https://www.cisa.gov/news-events/news/targeted-cyber-intrusion-detection-and-mitigation-strategies-update-b"
},
{
"category": "external",
"summary": "Recommended Practices",
"url": "https://www.cisa.gov/secure-our-world/teach-employees-avoid-phishing"
},
{
"category": "external",
"summary": "Recommended Practices",
"url": "https://www.cisa.gov/news-events/news/avoiding-social-engineering-and-phishing-attacks"
}
],
"title": "Honeywell IQ4 Series BMS Controller (Update A)",
"tracking": {
"current_release_date": "2026-03-26T06:00:00.000000Z",
"generator": {
"date": "2026-03-25T21:11:23.243110Z",
"engine": {
"name": "CISA CSAF Generator",
"version": "1.0.0"
}
},
"id": "ICSA-26-069-03",
"initial_release_date": "2026-03-10T06:00:00.000000Z",
"revision_history": [
{
"date": "2026-03-10T06:00:00.000000Z",
"legacy_version": "Initial",
"number": "1",
"summary": "Initial Publication"
},
{
"date": "2026-03-26T06:00:00.000000Z",
"legacy_version": "Update A",
"number": "2",
"summary": "Update A - Revised Affected Versions, updated vulnerability description and scores, and revised Mitigations to include the date of when secure default installations were enforced."
}
],
"status": "final",
"version": "2"
}
},
"product_tree": {
"branches": [
{
"branches": [
{
"branches": [
{
"category": "product_version_range",
"name": "\u003cv3.30",
"product": {
"name": "Honeywell IQ4E Firmware: \u003cv3.30",
"product_id": "CSAFPID-0001"
}
}
],
"category": "product_name",
"name": "IQ4E Firmware"
},
{
"branches": [
{
"category": "product_version_range",
"name": "\u003cv3.30",
"product": {
"name": "Honeywell IQ412 Firmware: \u003cv3.30",
"product_id": "CSAFPID-0002"
}
}
],
"category": "product_name",
"name": "IQ412 Firmware"
},
{
"branches": [
{
"category": "product_version_range",
"name": "\u003cv3.30",
"product": {
"name": "Honeywell IQ422 Firmware: \u003cv3.30",
"product_id": "CSAFPID-0003"
}
}
],
"category": "product_name",
"name": "IQ422 Firmware"
},
{
"branches": [
{
"category": "product_version_range",
"name": "\u003cv3.30",
"product": {
"name": "Honeywell IQ4NC Firmware: \u003cv3.30",
"product_id": "CSAFPID-0004"
}
}
],
"category": "product_name",
"name": "IQ4NC Firmware"
},
{
"branches": [
{
"category": "product_version_range",
"name": "\u003cv3.30",
"product": {
"name": "Honeywell IQ41x Firmware: \u003cv3.30",
"product_id": "CSAFPID-0005"
}
}
],
"category": "product_name",
"name": "IQ41x Firmware"
}
],
"category": "vendor",
"name": "Honeywell"
}
]
},
"vulnerabilities": [
{
"cve": "CVE-2026-3611",
"cwe": {
"id": "CWE-306",
"name": "Missing Authentication for Critical Function"
},
"notes": [
{
"category": "summary",
"text": "Prior to version 3.30, Honeywell IQ4 Series of building management controllers expose a web-based HMI without authentication in its factory-default configuration. With no user module configured, the system operates under a System Guest (level 100) context, granting read/write privileges to any party able to reach the HTTP interface. Authentication controls are enforced after a web user is created during commissioning, which dynamically enables the user module. Because this function is accessible prior to authentication, a remote user can create a new account with administrative read/write permissions enabling the user module and imposing authentication under attacker-controlled credentials. This action can effectively lock legitimate users out of the controller.",
"title": "Vulnerability Summary"
},
{
"category": "details",
"text": "SSVCv2/E:N/A:Y/2026-03-25T06:00:00.000000Z",
"title": "SSVC"
}
],
"product_status": {
"known_affected": [
"CSAFPID-0001",
"CSAFPID-0002",
"CSAFPID-0003",
"CSAFPID-0004",
"CSAFPID-0005"
]
},
"references": [
{
"category": "external",
"summary": "cwe.mitre.org",
"url": "https://cwe.mitre.org/data/definitions/306.html"
},
{
"category": "external",
"summary": "www.cve.org",
"url": "https://www.cve.org/CVERecord?id=CVE-2026-3611"
},
{
"category": "external",
"summary": "www.first.org",
"url": "https://www.first.org/cvss/calculator/3.1#CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"
},
{
"category": "external",
"summary": "www.first.org",
"url": "https://www.first.org/cvss/calculator/4.0#CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N"
}
],
"remediations": [
{
"category": "mitigation",
"details": "Version 3.30, released June 2015, and later force users to install a user module upon the commissioning of the device. This user module enables authentication and other security features for the web interface. When updating previously commissioned devices to firmware versions 3.30 or later (current version is 4.3x), users are not forced to install a user module unless they have changed their device configuration files after updating the firmware version. Honeywell recommends that users check their firmware versions and ensure that a user module has been set up to enable device security features, even if they are running firmware version 3.30 or later.",
"product_ids": [
"CSAFPID-0001",
"CSAFPID-0002",
"CSAFPID-0003",
"CSAFPID-0004",
"CSAFPID-0005"
]
},
{
"category": "mitigation",
"details": "Honeywell recommends that users with affected products take the following steps:",
"product_ids": [
"CSAFPID-0001",
"CSAFPID-0002",
"CSAFPID-0003",
"CSAFPID-0004",
"CSAFPID-0005"
]
},
{
"category": "mitigation",
"details": "Apply product updates as available.",
"product_ids": [
"CSAFPID-0001",
"CSAFPID-0002",
"CSAFPID-0003",
"CSAFPID-0004",
"CSAFPID-0005"
]
},
{
"category": "mitigation",
"details": "Follow guidance in the product security manual to ensure isolation of network segments hosting building automation controllers.",
"product_ids": [
"CSAFPID-0001",
"CSAFPID-0002",
"CSAFPID-0003",
"CSAFPID-0004",
"CSAFPID-0005"
]
},
{
"category": "mitigation",
"details": "Ensure adequate security controls are in place between OT and IT segments.",
"product_ids": [
"CSAFPID-0001",
"CSAFPID-0002",
"CSAFPID-0003",
"CSAFPID-0004",
"CSAFPID-0005"
]
},
{
"category": "mitigation",
"details": "Disable unnecessary accounts and services.",
"product_ids": [
"CSAFPID-0001",
"CSAFPID-0002",
"CSAFPID-0003",
"CSAFPID-0004",
"CSAFPID-0005"
]
},
{
"category": "mitigation",
"details": "Restrict system access to authorized personnel only and follow a least privilege approach.",
"product_ids": [
"CSAFPID-0001",
"CSAFPID-0002",
"CSAFPID-0003",
"CSAFPID-0004",
"CSAFPID-0005"
]
},
{
"category": "mitigation",
"details": "Apply defense-in-depth strategies.",
"product_ids": [
"CSAFPID-0001",
"CSAFPID-0002",
"CSAFPID-0003",
"CSAFPID-0004",
"CSAFPID-0005"
]
},
{
"category": "mitigation",
"details": "Log and monitor network traffic for suspicious activity.",
"product_ids": [
"CSAFPID-0001",
"CSAFPID-0002",
"CSAFPID-0003",
"CSAFPID-0004",
"CSAFPID-0005"
]
},
{
"category": "mitigation",
"details": "For IQ4 Series controllers, ensure the latest available firmware version is utilized. The latest firmware may be obtained from a dealer or the Trend Partner Network https://partners.trendcontrols.com/signin (login required).",
"product_ids": [
"CSAFPID-0001",
"CSAFPID-0002",
"CSAFPID-0003",
"CSAFPID-0004",
"CSAFPID-0005"
],
"url": "https://partners.trendcontrols.com/signin"
},
{
"category": "mitigation",
"details": "Follow the Security Best Practice for Trend Products included with product documentation. Additional copies may be obtained from a dealer or the Trend Partner Network https://partners.trendcontrols.com/signin (login required).",
"product_ids": [
"CSAFPID-0001",
"CSAFPID-0002",
"CSAFPID-0003",
"CSAFPID-0004",
"CSAFPID-0005"
],
"url": "https://partners.trendcontrols.com/signin"
}
],
"scores": [
{
"cvss_v3": {
"baseScore": 9.8,
"baseSeverity": "CRITICAL",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
"version": "3.1"
},
"products": [
"CSAFPID-0001",
"CSAFPID-0002",
"CSAFPID-0003",
"CSAFPID-0004",
"CSAFPID-0005"
]
}
]
}
]
}
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Experimental. This forecast is provided for visualization only and may change without notice. Do not use it for operational decisions.
Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
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The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the
vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base
model, served locally by ML-Gateway.
They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
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Related by attack behaviour
Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.
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