Generating the ECDSA nonce k samples a random number r and then truncates this randomness with a modular reduction mod n where n is the order of the elliptic curve. Meaning k = r mod n. The division used during the reduction estimates a factor q_e by dividing the upper two digits (a digit having e.g. a size of 8 byte) of r by the upper digit of n and then decrements q_e in a loop until it has the correct size. Observing the number of times q_e is decremented through a control-flow revealing side-channel reveals a bias in the most significant bits of k. Depending on the curve this is either a negligible bias or a significant bias large enough to reconstruct k with lattice reduction methods. For SECP160R1, e.g., we find a bias of 15 bits.

Fault Injection vulnerability in RsaPrivateDecryption function in wolfssl/wolfcrypt/src/rsa.c in WolfSSL wolfssl5.6.6 on Linux/Windows allows remote attacker co-resides in the same system with a victim process to disclose information and escalate privileges via Rowhammer fault injection to the RsaKey structure.

Fault Injection vulnerability in wc_ed25519_sign_msg function in wolfssl/wolfcrypt/src/ed25519.c in WolfSSL wolfssl5.6.6 on Linux/Windows allows remote attacker co-resides in the same system with a victim process to disclose information and escalate privileges via Rowhammer fault injection to the ed25519_key structure.