Firmware decryption via exposed SPI authentication password
Published Dec 10, 2024 · Updated Nov 3, 2025
Credential exposure in Siemens CPCI85 Central Processing/Communication before 05.30 allows physically proximate attackers to decrypt firmware updates. The secure element sends its authentication password over an unencrypted SPI bus, permitting capture and reuse of that credential as a decryption oracle. Physical access to the SPI bus is required, and the disclosed consequence is recovery of plaintext from encrypted update files rather than device control.
Summary
What happened
Credential exposure in Siemens CPCI85 Central Processing/Communication before 05.30 allows physically proximate attackers to decrypt firmware updates. The secure element sends its authentication password over an unencrypted SPI bus, permitting capture and reuse of that credential as a decryption oracle. Physical access to the SPI bus is required, and the disclosed consequence is recovery of plaintext from encrypted update files rather than device control.
The record
- CVE
- CVE-2024-53832
- Published
- Dec 10, 2024
- Updated
- Nov 3, 2025
- Vendor
- Siemens
- Product
- CPCI85 Central Processing/Communication
- Classifications
- CWE-522, T1140
- Attack vector
- physical
- Privileges
- unauthenticated
Timeline
How it unfolded
- Dec 10, 2024CVE publishedPublication date reported by the CVE source.
- Nov 3, 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 <V05.30
What conditions does exploitation require?
What is affected?
Published CVSS scores
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Attacks
What attackers are doing with it
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Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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