Detections
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CVE-2021-43572

critical

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

https://github.com/starkbank/ecdsa-python/releases/tag/v2.0.1

https://github.com/starkbank/ecdsa-python/commit/d136170666e9510eb63c2572551805807bd4c17f

https://research.nccgroup.com/2021/11/08/technical-advisory-arbitrary-signature-forgery-in-stark-bank-ecdsa-libraries/

Details

Source: Mitre, NVD

Published: 2021-11-09

Updated: 2026-06-17

Risk Information

CVSS v2

Base Score: 7.5

Vector: CVSS2#AV:N/AC:L/Au:N/C:P/I:P/A:P

Severity: High

CVSS v3

Base Score: 9.8

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Severity: Critical

EPSS

EPSS: 0.00229