PKCS#1 Version 1.5 Session Key Retrieval

The remote host is using version 1.5 of the SSH protocol. This version allows a remote attacker to decrypt and/or alter traffic via an attack against PKCS#1 version 1.5, called the ‘Bleichenbacher’ attack. OpenSSH up to version 2.3.0, AppGate and SSH Communications Security ssh1 update to version 1.2.31 are vulnerable to this attack.