Advisories for Pypi/Ecdsa package

2024

Minerva timing attack on P-256 in python-ecdsa

python-ecdsa has been found to be subject to a Minerva timing attack on the P-256 curve. Using the ecdsa.SigningKey.sign_digest() API function and timing signatures an attacker can leak the internal nonce which may allow for private key discovery. Both ECDSA signatures, key generation, and ECDH operations are affected. ECDSA signature verification is unaffected. The python-ecdsa project considers side channel attacks out of scope for the project and there is no …

2020

Improper Verification of Cryptographic Signature in Pure-Python ECDSA

A flaw was found in all python-ecdsa versions before 0.13.3, where it did not correctly verify whether signatures used DER encoding. Without this verification, a malformed signature could be accepted, making the signature malleable. Without proper verification, an attacker could use a malleable signature to create false transactions.

2019

ecdsa Denial of Service vulnerability in signature verification and signature malleability

Code using VerifyingKey.verify() and VerifyingKey.verify_digest() may receive exceptions other than the documented BadSignatureError when signatures are malformed. If those other exceptions are not caught, they may lead to program termination and thus Denial of Service Code using VerifyingKey.verify() and VerifyingKey.verify_digest() with sigdecode option using ecdsa.util.sigdecode_der will accept signatures even if they are not properly formatted DER. This makes the signatures malleable. It impacts only applications that later sign the signatures …