Secret-key recovery via bottom-bit collision timing
Published Jul 28, 2021 · Updated Aug 4, 2024
Key-recovery weakness in Meow hash 0.5/calico allows remote attackers to recover its 1024-bit secret key through collision-oracle queries. A differential characteristic in the message-absorption function survives with about 2^-45 probability, enabling bottom-bit collision tests to reveal key material. Exploitation requires roughly 2^49 chosen-message queries and a service whose timing exposes hash collisions; the recovered key enables forged same-length message collisions.
Summary
What happened
Key-recovery weakness in Meow hash 0.5/calico allows remote attackers to recover its 1024-bit secret key through collision-oracle queries. A differential characteristic in the message-absorption function survives with about 2^-45 probability, enabling bottom-bit collision tests to reveal key material. Exploitation requires roughly 2^49 chosen-message queries and a service whose timing exposes hash collisions; the recovered key enables forged same-length message collisions.
The record
- CVE
- CVE-2021-37606
- Published
- Jul 28, 2021
- Updated
- Aug 4, 2024
- Vendor
- Unknown vendor
- Product
- Unknown product
- Classifications
- CWE-326, CWE-203
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jul 28, 2021CVE publishedPublication date reported by the CVE source.
- Aug 4, 2024Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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What is affected?
Affected products and versions are unavailable in this record.
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.
Public exploit references
- Cryptanalysis of Meow Hashproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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