GHSA-vjh7-7g9h-fjfh: Elliptic's private key extraction in ECDSA upon signing a malformed input (e.g. a string)

Private key can be extracted from ECDSA signature upon signing a malformed input (e.g. a string or a number), which could e.g. come from JSON network input

Note that elliptic by design accepts hex strings as one of the possible input types