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CVE-2025-14505

Elliptic Cryptanalysis vulnerability when `k` has leading zeros

CVSS 5.6 MEDIUMEPSS 0.2%CWE-1240
In short

The Elliptic cryptographic library incorrectly handles certain values during ECDSA signature generation, causing signatures to be invalid or weak. An attacker with access to both a faulty and correct signature could potentially recover the secret key used to sign messages.

Technical detail

ECDSA signature generation in Elliptic truncates the interim value 'k' when it contains leading zeros due to incorrect byte-length computation during RFC 6979 deterministic nonce generation. This cryptanalytic weakness allows an attacker who obtains paired faulty and correct signatures for the same message to derive the private key through differential analysis, compromising the entire cryptographic system.

Summary generated and translated by AI from the official description.
The ECDSA implementation of the Elliptic package generates incorrect signatures if an interim value of 'k' (as computed based on step 3.2 of RFC 6979 https://datatracker.ietf.org/doc/html/rfc6979 ) has leading zeros and is susceptible to cryptanalysis, which can lead to secret key exposure. This happens, because the byte-length of 'k' is incorrectly computed, resulting in its getting truncated during the computation. Legitimate transactions or communications will be broken as a result. Furthermore, due to the nature of the fault, attackers could–under certain conditions–derive the secret key, if they could get their hands on both a faulty signature generated by a vulnerable version of Elliptic and a correct signature for the same inputs. This issue affects all known versions of Elliptic (at the time of writing, versions less than or equal to 6.6.1).
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L
Affected products
N/A · Elliptic

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