Private-key extraction via nonce-dependent signing time
Published Jun 16, 2025 · Updated Jun 26, 2025
Timing leakage in OpenSSL 3.0.0 through 3.3.2 on PowerPC allows local users to extract P-384 ECDSA private keys. EVP_DigestSign execution time varies with the bit length of nonce K, enabling statistical separation of signatures using smaller and full-sized nonces. Exploitation requires an attacking process on the same physical system to measure many signatures, and OpenSSL disputes that this scenario falls within its threat model.
Summary
What happened
Timing leakage in OpenSSL 3.0.0 through 3.3.2 on PowerPC allows local users to extract P-384 ECDSA private keys. EVP_DigestSign execution time varies with the bit length of nonce K, enabling statistical separation of signatures using smaller and full-sized nonces. Exploitation requires an attacking process on the same physical system to measure many signatures, and OpenSSL disputes that this scenario falls within its threat model.
The record
- CVE
- CVE-2025-27587
- Published
- Jun 16, 2025
- Updated
- Jun 26, 2025
- Vendor
- Unknown vendor
- Product
- Unknown product
- Classifications
- CWE-385
- Attack vector
- local
- Privileges
- Unavailable
Timeline
How it unfolded
- Jun 16, 2025CVE publishedPublication date reported by the CVE source.
- Jun 26, 2025Record updatedLatest update available in the CVE record.
Exploitability
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What is affected?
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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
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Your stack
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