CVE-2016-0739

libssh en versiones anteriores a 0.7.3 trunca de manera incorrecta secretos efímeros generados para los métodos de intercambio de clave (1) diffie-hellman-group1 y (2) diffie-hellman-group14 a 128 bits, lo que hace más fácil a atacantes man-in-the-middle descifrar o interceptar sesiones SSH a través de vectores no especificados, también conocido como "bits/bytes confusion bug".

A type confusion issue was found in the way libssh generated ephemeral secrets for the diffie-hellman-group1 and diffie-hellman-group14 key exchange methods. This would cause an SSHv2 Diffie-Hellman handshake to use significantly less secure random parameters.

Mariusz Ziulek discovered that libssh incorrectly handled certain packets. A remote attacker could possibly use this issue to cause libssh to crash, resulting in a denial of service. Aris Adamantiadis discovered that libssh incorrectly generated ephemeral secret keys of 128 bits instead of the recommended 1024 or 2048 bits when using the diffie-hellman-group1 and diffie-hellman-group14 methods. If a remote attacker were able to perform a man-in-the-middle attack, this flaw could be exploited to view sensitive information. Various other issues were also addressed.