{ "document": { "acknowledgments": [ { "names": [ "Qiguang Zhang", " Zhen Ling", "Junzhou Luo", "Chongqing Lei" ], "organization": "Southeast University;" }, { "names": [ "Xinwen Fu" ], "organization": "University of Massachusetts Lowell and " }, { "names": [ "Yue Zhang" ], "organization": "Shandong University - ", "summary": "reporting this vulnerability through responsible disclosure." } ], "category": "csaf_security_advisory", "csaf_version": "2.0", "distribution": { "tlp": { "label": "WHITE" } }, "lang": "en", "notes": [ { "category": "summary", "text": "ABB has been contacted by a researcher who identified a vulnerability in one of its products. ABB has been contacted by a researcher who identified a vulnerability in one of its products. The vulnerability report has been shared in responsible disclosure. \n\nAn attacker who successfully exploited this vulnerability could cause the product to become unusable.\nABB confirms the vulnerability but at the same time acknowledges that the issue affects exclusively classic KNX devices that are not supporting the latest KNX Secure standard. Due to a lack of security in legacy KNX devices, the issue cannot be resolved via a software change. In order to actively exploit this vulnerability, an attacker requires physical access to the bus, the affected device is connected to.\n\nABB has no plans of corrective measures. ", "title": "Summary" }, { "category": "other", "text": "For additional instructions and support please contact your local ABB service organization. For contact information, see www.abb.com/contactcenters.\n\nInformation about ABB’s cyber security program and capabilities can be found at www.abb.com/cybersecurity.", "title": "Support" }, { "category": "legal_disclaimer", "text": "The information in this document is subject to change without notice, and should not be construed as a commitment by ABB.\n\nABB provides no warranty, express or implied, including warranties of merchantability and fitness for a particular purpose, for the information contained in this document, and assumes no responsibility for any errors that may appear in this document. In no event shall ABB or any of its suppliers be liable for direct, indirect, special, incidental or consequential damages of any nature or kind arising from the use of this document, or from the use of any hardware or software described in this document, even if ABB or its suppliers have been advised of the possibility of such damages.\n\nThis document and parts hereof must not be reproduced or copied without written permission from ABB, and the contents hereof must not be imparted to a third party nor used for any unauthorized purpose.\n\nAll rights to registrations and trademarks reside with their respective owners.\n", "title": "Notice" }, { "category": "other", "text": "ABB strongly recommends customers to follow the steps described in section: Error! Reference source not found.. In addition, it is recommended to:\n\n- Harden the KNX system by only allowing operations and services necessary for the specified functionality of that system.\n\n- Isolate special purpose networks (e.g. for automation systems) and remote devices behind firewalls and separate them from any general-purpose network (e.g. office or home networks).\n\n- Install physical controls so no unauthorized personnel can access your devices, components, peripheral equipment, and networks.\n\n- Never connect programming software or computers containing programing software to any net-work other than the network for the devices that it is intended for.\n\n- Scan all data imported into your environment before use to detect potential malware infections.\n\n- Minimize network exposure for all applications and endpoints to ensure that they are not accessible from the Internet unless they are designed for such exposure and the intended use requires such.\n\n- Ensure all nodes are always up to date in terms of installed software, operating system, and firmware patches as well as anti-virus and firewall.\n\n- When remote access is required, use secure methods, such as Virtual Private Networks (VPNs). Recognize that VPNs may have vulnerabilities and should be updated to the most current version available.\nAlso, understand that VPNs are only as secure as the connected devices.\n\nMore information on recommended practices can be found in the documents listed in the Error! Reference source not found. section.\n", "title": "General security recommendations" }, { "category": "other", "text": "ABB has a rigorous internal cyber security continuous improvement process which involves regular testing with industry leading tools and periodic assessments to identify potential product issues. Occasionally an issue is determined to be a design or coding flaw with implications that may impact product cyber security.\n\nWhen a potential product vulnerability is identified or reported, ABB immediately initiates our vulnerability handling process. This entails validating if the issue is in fact a product issue, identifying root causes, determining what related products may be impacted, developing a remediation, and notifying end users and governmental organizations.\n\nThe resulting Cyber Security Advisory intends to notify customers of the vulnerability and provide details on which products are impacted, how to mitigate the vulnerability or explain workarounds that minimize the potential risk as much as possible. The release of a Cyber Security Advisory should not be misconstrued as an affirmation or indication of an active threat or ongoing campaign targeting the products mentioned here. If ABB is aware of any specific threats, it will be clearly mentioned in the communication.\n\nThe publication of this Cyber Security Advisory is an example of ABB’s commitment to the user community in support of this critical topic. Responsible disclosure is an important element in the chain of trust we work to maintain with our many customers. The release of an Advisory provides timely information which is essential to help ensure our customers are fully informed.", "title": "Purpose" }, { "category": "faq", "text": "What causes the vulnerability?\n- The vulnerability is a result of missing security features which were never specified for ABB legacy KNX products.\n\nWhat is BJE/ABB Firmware-Update 2.0?\n- The ETS app “ABB Firmware Update 2.0” and “BJE Firmware Update 2.0” is used to update the firmware of various ABB KNX devices directly via the KNX bus. The latest firmware files can be downloaded automatically from the Internet or imported manually.\n\n The app can be used with ETS 5 or later.\n\nWhat might an attacker use the vulnerability to do?\n- An attacker who successfully exploited this vulnerability could cause the affected product to stop working properly if physical access is given to the bus, the product is connected to. In cases the attacker is capable to reverse engineer the firmware of the product, (s)he could change the product behavior. It is a duty of the product and system owner to ensure that physical access to the field bus is limited to authorized personal.\n\nHow could an attacker exploit the vulnerability?\n- An attacker could try to exploit the vulnerability by tampering the firmware image or intercept the data flow between the device and the firmware update tool.\n\nCould the vulnerability be exploited remotely?\n- No, to exploit this vulnerability an attacker would need to have physical access to an affected system node. It is assumed that the system is set up in accordance with commonly accepted security practices.\n\nCan functional safety be affected by an exploit of this vulnerability?\n- KNX devices are not in scope of functional safety standards.\n\nWhy does ABB have no plans for corrective measures?\n- The security features, that are needed to fix this vulnerability with a perfect technical approach, cannot be delivered with a Software update.\n\nWhen this security advisory was issued, had this vulnerability been publicly disclosed?\n- No, ABB received information about this vulnerability through responsible disclosure. \n\nWhen this security advisory was issued, had ABB received any reports that this vulnerability was being exploited?\n- No, ABB had not received any information indicating that this vulnerability had been exploited when this security advisory was originally issued.", "title": "Frequently Asked Questions" } ], "publisher": { "category": "vendor", "name": "ABB PSIRT", "namespace": "https://www.abb.com/global/en/company/about/cybersecurity/alerts-and-notifications" }, "references": [ { "category": "self", "summary": "ABB CYBERSECURITY ADVISORY - PDF Version ", "url": "https://search.abb.com/library/Download.aspx?DocumentID=9AKK108472A9270&LanguageCode=en&DocumentPartId=pdf&Action=Launch" }, { "category": "self", "summary": "ABB CYBERSECURITY ADVISORY - CSAF Version ", "url": "https://psirt.abb.com/csaf/2026/9akk108472a9270.json" }, { "summary": "Cybersecurity Protection for Smart Buildings ", "url": "https://new.abb.com/low-voltage/products/building-automation/product-range/abb-i-bus-knx/cybersecurity-protection-for-smart-buildings" } ], "title": "ABB/EL/ELSB/Building Automation File integrity can be bypassed in KNX Update Tool for classic KNX products", "tracking": { "current_release_date": "2026-07-17T00:30:00.000Z", "generator": { "date": "2026-07-17T11:54:30.836Z", "engine": { "name": "Secvisogram", "version": "2.6.6" } }, "id": "9AKK108472A9270", "initial_release_date": "2026-07-17T00:30:00.000Z", "revision_history": [ { "date": "2026-07-17T00:30:00.000Z", "legacy_version": "A", "number": "1", "summary": "Initial version" } ], "status": "final", "version": "1" } }, "product_tree": { "branches": [ { "branches": [ { "branches": [ { "category": "product_version_range", "name": "<=2.0.175", "product": { "name": "KNX Update Tool (ABB) <=2.0.175", "product_id": "AV1" } } ], "category": "product_name", "name": "KNX Update Tool (ABB)" }, { "branches": [ { "category": "product_version_range", "name": "<=2.0.175", "product": { "name": "KNX Update Tool (BJE) <=2.0.175", "product_id": "AV2" } } ], "category": "product_name", "name": "KNX Update Tool (BJE)" } ], "category": "vendor", "name": "ABB" } ] }, "vulnerabilities": [ { "cve": "CVE-2026-12705", "cwe": { "id": "CWE-353", "name": "Missing Support for Integrity Check" }, "notes": [ { "category": "description", "text": "There is no protection of the integrity of the firmware image. This applies exclusively to legacy KNX products", "title": "CVE description" } ], "product_status": { "known_affected": [ "AV1", "AV2" ] }, "references": [ { "category": "external", "summary": "NVD - CVE-2026-12705", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-12705" } ], "remediations": [ { "category": "mitigation", "details": "Due to the nature of the classic KNX protocol stack and security concept, there are no options to resolve the vulnerability with a software update on a technical level.\n\nABB recommends to follow general security recommendations listed in the security guideline (see References and General security recommendations). In addition, it shall be avoided to control sensitive functionality by legacy KNX devices such as, but not limited to, access control to e.g. hotel rooms or other protected areas.\n\nNote: Legacy KNX standards were never designed to meet state of the art security standards like introduced with KNX Data Secure published in 2017.", "product_ids": [ "AV1", "AV2" ] } ], "scores": [ { "cvss_v3": { "attackComplexity": "HIGH", "attackVector": "ADJACENT_NETWORK", "availabilityImpact": "HIGH", "baseScore": 6.4, "baseSeverity": "MEDIUM", "confidentialityImpact": "NONE", "environmentalScore": 6.3, "environmentalSeverity": "MEDIUM", "exploitCodeMaturity": "FUNCTIONAL", "integrityImpact": "HIGH", "privilegesRequired": "LOW", "remediationLevel": "UNAVAILABLE", "reportConfidence": "CONFIRMED", "scope": "UNCHANGED", "temporalScore": 6.3, "temporalSeverity": "MEDIUM", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:A/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:H/E:F/RL:U/RC:C", "version": "3.1" }, "products": [ "AV1", "AV2" ] } ], "title": "CVE-2026-12705" } ] }