Malicious firmware installation via improper signature verification
Published May 23, 2025 · Updated Dec 9, 2025
Improper firmware signature verification in Siemens Building X Security Manager Edge Controller ACC-AP allows attackers to install modified firmware. The firmware update path accepts update images without properly verifying their cryptographic signatures before installation. Exploitation requires local update access or a man-in-the-middle position during a legitimate transfer and permits persistent replacement of controller firmware.
Summary
What happened
Improper firmware signature verification in Siemens Building X Security Manager Edge Controller ACC-AP allows attackers to install modified firmware. The firmware update path accepts update images without properly verifying their cryptographic signatures before installation. Exploitation requires local update access or a man-in-the-middle position during a legitimate transfer and permits persistent replacement of controller firmware.
The record
- CVE
- CVE-2022-31807
- Published
- May 23, 2025
- Updated
- Dec 9, 2025
- Vendor
- Siemens
- Product
- Building X Security Manager Edge Controller (ACC-AP)
- Classifications
- CWE-347, T1601.001
- Attack vector
- local
- Privileges
- unauthenticated
Timeline
How it unfolded
- May 23, 2025CVE publishedPublication date reported by the CVE source.
- Dec 9, 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?
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- Affected versionversion=0 <*
What conditions does exploitation require?
What is affected?
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
No public exploit references are available in this record.
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Technologies
Your stack
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Your stack
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