Description
The verify function in the Stark Bank Python ECDSA library (aka starkbank-escada or ecdsa-python) before 2.0.1 fails to check that the signature is non-zero, which allows attackers to forge signatures on arbitrary messages.
References (3)
Core 3
Core References
Exploit, Third Party Advisory x_refsource_misc
https://research.nccgroup.com/2021/11/08/technical-advisory-arbitrary-signature-forgery-in-stark-bank-ecdsa-libraries/
Release Notes, Third Party Advisory x_refsource_misc
https://github.com/starkbank/ecdsa-python/releases/tag/v2.0.1
Patch, Third Party Advisory x_refsource_misc
https://github.com/starkbank/ecdsa-python/commit/d136170666e9510eb63c2572551805807bd4c17f
Scores
CVSS v3
9.8
EPSS
0.0120
EPSS Percentile
64.1%
Attack Vector
NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Details
CWE
CWE-347
Status
published
Products (2)
pypi/starkbank-ecdsa
0 - 2.0.1PyPI
starkbank/ecdsa-python
< 2.0.1
Published
Nov 09, 2021
Tracked Since
Feb 18, 2026