Data disclosure via stale symmetric-cipher initialization vectors
Published Mar 25, 2021 · Updated Aug 3, 2024
Cryptographic IV reuse in libtpms before 0.8.2 allows local users to weaken chained encryption and expose protected data. The OpenSSL paths in CryptSymmetricEncrypt and CryptSymmetricDecrypt leave ivInOut holding the input IV instead of copying the cipher context's final IV. Exploitation requires low-privileged local access to a TPM 2 consumer built with OpenSSL and a cipher mode that carries IV state; integrity and service availability are unaffected.
Summary
What happened
Cryptographic IV reuse in libtpms before 0.8.2 allows local users to weaken chained encryption and expose protected data. The OpenSSL paths in CryptSymmetricEncrypt and CryptSymmetricDecrypt leave ivInOut holding the input IV instead of copying the cipher context's final IV. Exploitation requires low-privileged local access to a TPM 2 consumer built with OpenSSL and a cipher mode that carries IV state; integrity and service availability are unaffected.
The record
- CVE
- CVE-2021-3446
- Published
- Mar 25, 2021
- Updated
- Aug 3, 2024
- Vendor
- libtpms Project
- Product
- libtpms
- Classifications
- CWE-327, CWE-330
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Mar 25, 2021CVE publishedPublication date reported by the CVE source.
- Aug 3, 2024Record 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=libtpms 0.8.2
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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