Device impersonation via exposed factory setup key
Published Jun 5, 2024 · Updated Sep 17, 2025
FDSK exposure in ABB displays 1.00 and BCU 1.3.0.33 allows physically proximate attackers to impersonate affected devices. A crafted KNX bus message reveals the FDSK while a device is not operating in KNX Secure mode; captured commissioning traffic can then be decrypted to recover communication keys. Physical KNX-network access at commissioning time is required, and recovered keys permit forged telegrams that operate connected building actuators.
Summary
What happened
FDSK exposure in ABB displays 1.00 and BCU 1.3.0.33 allows physically proximate attackers to impersonate affected devices. A crafted KNX bus message reveals the FDSK while a device is not operating in KNX Secure mode; captured commissioning traffic can then be decrypted to recover communication keys. Physical KNX-network access at commissioning time is required, and recovered keys permit forged telegrams that operate connected building actuators.
The record
- CVE
- CVE-2024-4008
- Published
- Jun 5, 2024
- Updated
- Sep 17, 2025
- Vendor
- GENEREX SYSTEMS Computervertriebsgesellschaft mbH
- Product
- BCU KNX, BA-U1.0.21
- Classifications
- CWE-497, T1040
- Attack vector
- adjacent
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jun 5, 2024CVE publishedPublication date reported by the CVE source.
- Sep 17, 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.
- Affected versionversion=1.3.0.33
What conditions does exploitation require?
What is affected?
Published CVSS scores
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.
Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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