{"id":"CVE-2026-3611","state":"PUBLISHED","title":"Honeywell IQ4x BMS Controller Missing authentication for critical function","description":"The Honeywell IQ4x building management controller, exposes its full web-based HMI without authentication in its factory-default configuration. With no user module configured, security is disabled by design and 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 only enforced after a web user is created via U.htm, 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 operators out of local and web-based configuration and administration.","publishedAt":"2026-03-12T20:06:05.753Z","updatedAt":"2026-03-30T15:26:08.604Z","severity":{"score":10,"label":"Critical","version":"4.0","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H","source":"icscert"},"assigner":"icscert","products":["Honeywell IQ4E","Honeywell IQ412","Honeywell IQ422","Honeywell IQ4NC","Honeywell IQ41x","Honeywell IQ3","Honeywell IQECO"],"affected":[{"vendor":"Honeywell","product":"IQ4E","defaultStatus":"unaffected","versions":[{"version":"v3.50_3.44","status":"affected","lessThanOrEqual":"4.36 (build 4.3.7.9)","versionType":"custom"}]},{"vendor":"Honeywell","product":"IQ412","defaultStatus":"unaffected","versions":[{"version":"v3.50_3.44","status":"affected","lessThanOrEqual":"4.36 (build 4.3.7.9)","versionType":"custom"}]},{"vendor":"Honeywell","product":"IQ422","defaultStatus":"unaffected","versions":[{"version":"v3.50_3.44","status":"affected","lessThanOrEqual":"4.36 (build 4.3.7.9)","versionType":"custom"}]},{"vendor":"Honeywell","product":"IQ4NC","defaultStatus":"unaffected","versions":[{"version":"v3.50_3.44","status":"affected","lessThanOrEqual":"4.36 (build 4.3.7.9)","versionType":"custom"}]},{"vendor":"Honeywell","product":"IQ41x","defaultStatus":"unaffected","versions":[{"version":"v3.50_3.44","status":"affected","lessThanOrEqual":"4.36 (build 4.3.7.9)","versionType":"custom"}]},{"vendor":"Honeywell","product":"IQ3","defaultStatus":"unaffected","versions":[{"version":"v3.50_3.44","status":"affected","lessThanOrEqual":"4.36 (build 4.3.7.9)","versionType":"custom"}]},{"vendor":"Honeywell","product":"IQECO","defaultStatus":"unaffected","versions":[{"version":"v3.50_3.44","status":"affected","lessThanOrEqual":"4.36 (build 4.3.7.9)","versionType":"custom"}]}],"references":["https://www.cisa.gov/news-events/ics-advisories/icsa-26-069-03","https://github.com/cisagov/CSAF/blob/develop/csaf_files/OT/white/2026/icsa-26-069-03.json","https://www.honeywell.com/us/en/contact"],"weaknesses":["CWE-306"],"ingestedAt":"2026-10-29T20:11:50.837Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/3xxx/CVE-2026-3611.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-3611","state":"PUBLISHED","datePublished":"2026-03-12T20:06:05.753Z","dateUpdated":"2026-03-30T15:26:08.604Z","assignerShortName":"icscert","assignerOrgId":"7d14cffa-0d7d-4270-9dc0-52cabd5a23a6","dateReserved":"2026-03-05T18:12:38.425Z"},"containers":{"cna":{"title":"Honeywell IQ4x BMS Controller Missing authentication for critical function","descriptions":[{"lang":"en","value":"The Honeywell IQ4x building management controller, exposes its full web-based HMI without authentication in its factory-default configuration. With no user module configured, security is disabled by design and 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 only enforced after a web user is created via U.htm, 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 operators out of local and web-based configuration and administration."}],"affected":[{"vendor":"Honeywell","product":"IQ4E","defaultStatus":"unaffected","versions":[{"version":"v3.50_3.44","status":"affected","lessThanOrEqual":"4.36 (build 4.3.7.9)","versionType":"custom"}]},{"vendor":"Honeywell","product":"IQ412","defaultStatus":"unaffected","versions":[{"version":"v3.50_3.44","status":"affected","lessThanOrEqual":"4.36 (build 4.3.7.9)","versionType":"custom"}]},{"vendor":"Honeywell","product":"IQ422","defaultStatus":"unaffected","versions":[{"version":"v3.50_3.44","status":"affected","lessThanOrEqual":"4.36 (build 4.3.7.9)","versionType":"custom"}]},{"vendor":"Honeywell","product":"IQ4NC","defaultStatus":"unaffected","versions":[{"version":"v3.50_3.44","status":"affected","lessThanOrEqual":"4.36 (build 4.3.7.9)","versionType":"custom"}]},{"vendor":"Honeywell","product":"IQ41x","defaultStatus":"unaffected","versions":[{"version":"v3.50_3.44","status":"affected","lessThanOrEqual":"4.36 (build 4.3.7.9)","versionType":"custom"}]},{"vendor":"Honeywell","product":"IQ3","defaultStatus":"unaffected","versions":[{"version":"v3.50_3.44","status":"affected","lessThanOrEqual":"4.36 (build 4.3.7.9)","versionType":"custom"}]},{"vendor":"Honeywell","product":"IQECO","defaultStatus":"unaffected","versions":[{"version":"v3.50_3.44","status":"affected","lessThanOrEqual":"4.36 (build 4.3.7.9)","versionType":"custom"}]}],"references":[{"url":"https://www.cisa.gov/news-events/ics-advisories/icsa-26-069-03"},{"url":"https://github.com/cisagov/CSAF/blob/develop/csaf_files/OT/white/2026/icsa-26-069-03.json"},{"url":"https://www.honeywell.com/us/en/contact"}],"metrics":[{"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}],"cvssV4_0":{"attackVector":"NETWORK","attackComplexity":"LOW","attackRequirements":"NONE","privilegesRequired":"NONE","userInteraction":"NONE","vulnConfidentialityImpact":"HIGH","subConfidentialityImpact":"HIGH","vulnIntegrityImpact":"HIGH","subIntegrityImpact":"HIGH","vulnAvailabilityImpact":"HIGH","subAvailabilityImpact":"HIGH","exploitMaturity":"NOT_DEFINED","Safety":"NOT_DEFINED","Automatable":"NOT_DEFINED","Recovery":"NOT_DEFINED","valueDensity":"NOT_DEFINED","vulnerabilityResponseEffort":"NOT_DEFINED","providerUrgency":"NOT_DEFINED","version":"4.0","baseSeverity":"CRITICAL","baseScore":10,"vectorString":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H"}},{"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}],"cvssV3_1":{"version":"3.1","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"NONE","scope":"CHANGED","confidentialityImpact":"HIGH","integrityImpact":"HIGH","availabilityImpact":"HIGH","baseSeverity":"CRITICAL","baseScore":10,"vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-306","lang":"en","description":"CWE-306 Missing authentication for critical function","type":"CWE"}]}],"providerMetadata":{"shortName":"icscert","orgId":"7d14cffa-0d7d-4270-9dc0-52cabd5a23a6","dateUpdated":"2026-03-30T15:26:08.604Z"},"datePublic":"2026-03-10T17:00:00.000Z","workarounds":[{"lang":"en","value":"Honeywell is aware of the issue, but has not released a fix. For more \ninformation, contact Honeywell directly. \n[https://www.honeywell.com/us/en/contact](https://www.honeywell.com/us/en/contact).","supportingMedia":[{"type":"text/html","base64":false,"value":"Honeywell is aware of the issue, but has not released a fix. For more \ninformation, contact Honeywell directly. \n[https://www.honeywell.com/us/en/contact](https://www.honeywell.com/us/en/contact)."}]}],"credits":[{"lang":"en","value":"Gjoko Krstic of Zero Science reported this vulnerability to Honeywell.","type":"finder"}],"source":{"advisory":"ICSA-26-069-03","discovery":"EXTERNAL"},"x_generator":{"engine":"Vulnogram 1.0.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-03-13T18:02:46.954644Z","id":"CVE-2026-3611","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"Technical Impact":"total"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-03-13T18:03:02.081Z"}}]}}}