The verify function in the Stark Bank Python ECDSA library (starkbank-ecdsa) 2.0.0 fails to check that the signature is non-zero, which allows attackers to forge signatures on arbitrary messages.
An attacker can forge signatures on arbitrary messages that will verify for any public key. This may allow attackers to authenticate as any user within the Stark Bank platform, and bypass signature verification needed to perform operations on the platform, such as send payments and transfer funds. Additionally, the ability for attackers to forge signatures may impact other users and projects using these libraries in different and unforeseen ways.