Key disclosure via fixed AES wrapping key
Published Jun 4, 2021 · Updated Aug 3, 2024
Improper initialization in TPM2 Software tpm2-tools before 5.1.1 and before 4.3.2 allows man-in-the-middle attackers to read imported keys. The tpm2_import key_import routine filled the inner-wrapper AES key buffer with constant 0xFF bytes instead of generating random key material. Exploitation requires control of the tool-to-TPM communication path and discloses the imported private key; an encrypted TPM session does not protect the fixed wrapping key.
Summary
What happened
Improper initialization in TPM2 Software tpm2-tools before 5.1.1 and before 4.3.2 allows man-in-the-middle attackers to read imported keys. The tpm2_import key_import routine filled the inner-wrapper AES key buffer with constant 0xFF bytes instead of generating random key material. Exploitation requires control of the tool-to-TPM communication path and discloses the imported private key; an encrypted TPM session does not protect the fixed wrapping key.
The record
- CVE
- CVE-2021-3565
- Published
- Jun 4, 2021
- Updated
- Aug 3, 2024
- Vendor
- TPM2 Software
- Product
- tpm2-tools
- Classifications
- CWE-665, CWE-798, T1557
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jun 4, 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?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=tpm2-tools 5.1.1, tpm2-tools 4.3.2
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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