Heap-based buffer overflow in the KCAPI ECC code path of wc_ecc_import_x963_ex() in wolfSSL wolfcrypt allows a remote attacker to write attacker-controlled data past the bounds of the pubkey_raw buffer via a crafted oversized EC public key point. The WOLFSSL_KCAPI_ECC code path copies the input to key->pubkey_raw (132 bytes) using XMEMCPY without a bounds check, unlike the ATECC code path which includes a length validation. This can be triggered during TLS key exchange when a malicious peer sends a crafted ECPoint in ServerKeyExchange.
Build wolfSSL without WOLFSSL_KCAPI_ECC (this define is not enabled by default).
Update to the wolfSSL version containing the fix from PR #9988, which adds a bounds check on inLen before the XMEMCPY to pubkey_raw in the KCAPI ECC code path.