Observable Discrepancy
wolfSSL and wolfCrypt 4.0.0 and earlier (when configured without –enable-fpecc, –enable-sp, or –enable-sp-math) contain a timing side channel in ECDSA signature generation. This allows a local attacker, able to precisely measure the duration of signature operations, to infer information about the nonces used and potentially mount a lattice attack to recover the private key used. The issue occurs because ecc.c scalar multiplication might leak the bit length.