Incorrect Success Return vulnerability in the ssh_kdf() function of libssh when built with OpenSSL versions prior to 3.0. This issue arises because libssh interprets OpenSSL's return value 0 (indicating failure) as SSH_OK (indicating success). As a result, on failure, the function may return success without initializing the output key buffers. This can lead to the use of uninitialized cryptographic keys, affecting the encryption and decryption of SSH traffic. The vulnerability allows an attacker to exploit improper key handling, potentially resulting in data leakage, integrity issues, or denial of service during SSH communication.