libssh before 0.7.3 improperly truncates ephemeral secrets generated for
the (1) diffie-hellman-group1 and (2) diffie-hellman-group14 key exchange
methods to 128 bits, which makes it easier for man-in-the-middle attackers
to decrypt or intercept SSH sessions via unspecified vectors, aka a
"bits/bytes confusion bug."

mdeslaur