CVE-2021-43569: Starkbank Ecdsa-Dotnet

Critical severity, CVSS 9.8. EPSS: 1.1% chance of exploitation in the next 30 days.

The verify function in the Stark Bank .NET ECDSA library (ecdsa-dotnet) 1.3.1 fails to check that the signature is non-zero, which allows attackers to forge signatures on arbitrary messages.

Affected products

• Starkbank Ecdsa-Dotnet: version 1.3.2 only

Published 2021-11-09. Last modified 2026-06-17.