An issue was discovered in wolfSSL before 4.3.0 in a non-default configuration where DSA is enabled. DSA signing uses the BEEA algorithm during modular inversion of the nonce, leading to a side-channel attack against the nonce.
wolfSSL and wolfCrypt 4.1.0 and earlier (formerly known as CyaSSL) generate biased DSA nonces. This allows a remote attacker to compute the long term private key from several hundred DSA signatures via a lattice attack. The issue occurs because dsa.c fixes two bits of the generated nonces.
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.
In wolfSSL through 4.1.0, there is a missing sanity check of memory accesses in parsing ASN.1 certificate data while handshaking. Specifically, there is a one-byte heap-based buffer over-read in CheckCertSignature_ex in wolfcrypt/src/asn.c.
wolfSSL 4.0.0 has a Buffer Overflow in DoPreSharedKeys in tls13.c when a current identity size is greater than a client identity size. An attacker sends a crafted hello client packet over the network to a TLSv1.3 wolfSSL server. The length fields of the packet: record length, client hello length, total extensions length, PSK extension length, total identity length, and identity length contain their maximum value which is 2^16. The identity data field of the PSK extension of the packet contains the attack data, to be stored in the undefined memory (RAM) of the server. The size of the data is about 65 kB. Possibly the attacker can perform a remote code execution attack.