Plaintext recovery via CBC padding timing oracle
Published Dec 21, 2023 · Updated Apr 23, 2025
Observable timing discrepancy in Silicon Labs Gecko SDK before 4.4.0 allows physically proximate attackers to recover CBC plaintext. The CBC PKCS7 padding calculation takes observably different time when processing attacker-controlled ciphertext, creating a padding oracle; Silicon Labs has not identified the responsible function publicly. Exploitation requires repeated physical interaction with an affected ARM device and exposes protected plaintext without reported integrity or availability impact.
Summary
What happened
Observable timing discrepancy in Silicon Labs Gecko SDK before 4.4.0 allows physically proximate attackers to recover CBC plaintext. The CBC PKCS7 padding calculation takes observably different time when processing attacker-controlled ciphertext, creating a padding oracle; Silicon Labs has not identified the responsible function publicly. Exploitation requires repeated physical interaction with an affected ARM device and exposes protected plaintext without reported integrity or availability impact.
The record
- CVE
- CVE-2023-41097
- Published
- Dec 21, 2023
- Updated
- Apr 23, 2025
- Vendor
- Sigma Designs
- Product
- Gecko SDK (GSDK)
- Classifications
- CWE-208, CWE-327, CWE-203, CAPEC-463
- Attack vector
- physical
- Privileges
- unauthenticated
Timeline
How it unfolded
- Dec 21, 2023CVE publishedPublication date reported by the CVE source.
- Apr 23, 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=0 <4.4.0
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
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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