An issue was discovered in the DTLS handshake implementation in wolfSSL before 4.5.0. Clear DTLS application_data messages in epoch 0 do not produce an out-of-order error. Instead, these messages are returned to the application.

An issue was discovered in wolfSSL before 4.5.0, when single precision is not employed. Local attackers can conduct a cache-timing attack against public key operations. These attackers may already have obtained sensitive information if the affected system has been used for private key operations (e.g., signing with a private key).

An issue was discovered in wolfSSL before 4.5.0. It mishandles the change_cipher_spec (CCS) message processing logic for TLS 1.3. If an attacker sends ChangeCipherSpec messages in a crafted way involving more than one in a row, the server becomes stuck in the ProcessReply() loop, i.e., a denial of service.

The private-key operations in ecc.c in wolfSSL before 4.4.0 do not use a constant-time modular inverse when mapping to affine coordinates, aka a "projective coordinates leak."

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 before 4.3.0 mishandles calls to wc_SignatureGenerateHash, leading to fault injection in RSA cryptography.

In wolfSSL before 4.3.0, wc_ecc_mulmod_ex does not properly resist side-channel attacks.

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.