CVE-2021-43572

Advisory

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.

Affected package

Affected versions

Fixed versions

Vulnerability changelog

The verify function in the Stark Bank Python ECDSA library (ecdsa-python) 2.0.0 fails to check that the signature is non-zero, which allows attackers to forge signatures on arbitrary messages. See CVE-2021-43572.


MISC:https://github.com/starkbank/ecdsa-python/releases/tag/v2.0.1: https://github.com/starkbank/ecdsa-python/releases/tag/v2.0.1
MISC:https://research.nccgroup.com/2021/11/08/technical-advisory-arbitrary-signature-forgery-in-stark-bank-ecdsa-libraries/: https://research.nccgroup.com/2021/11/08/technical-advisory-arbitrary-signature-forgery-in-stark-bank-ecdsa-libraries/

Resources

• https://github.com/starkbank/ecdsa-python/releases/tag/v2.0.1
• https://research.nccgroup.com/2021/11/08/technical-advisory-arbitrary-signature-forgery-in-stark-ban
• https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-43572
• https://research.nccgroup.com/2021/11/08/technical-advisory-arbitrary-signature-forgery-in-stark-bank-ecdsa-libraries/
• https://github.com/starkbank/ecdsa-python/commit/d136170666e9510eb63c2572551805807bd4c17f