Connecting via SSH to a QNAP NAS fails

I can't seem to connect to a QNAP NAS ssh session from within RDM (Enterprise, latest version 2020.2.19.0), I keep getting the following error:



That's strange because I can connect just fine from the command line (cmd.exe) on my Windows 10 computer. And I can also connect fine from another *nix System.

No keys involved, just user/password, from within the same subnet.

Any ideas why this is failing? I created a log, you'll find it below. It clearly says that the connection fails due to a user auth failure but that's not possible, both the login name (admin, I even checked for leading and trailing spaces) as well as the password are 100% correct, I checked it several times. Also, I just copied the password when connecting from the command line that's why I know for a fact that it's correct.

I don't have this issue with other ssh entries in RDM, just this one. That's why I even recreated it from scratch but the issue persists.

[25.09.2020 12:10:27] Starting SSH, verbose level: 2

[25.09.2020 12:10:27] Setting up connection

[25.09.2020 12:10:27] Connecting as admin

[25.09.2020 12:10:27] SSH banner: SSH-2.0-OpenSSH_8.0


[25.09.2020 12:10:27] Sending kex init

[25.09.2020 12:10:27] Received kex init

[25.09.2020 12:10:27] Selected algorithms: curve25519-sha256, rsa-sha2-256, chacha20-poly1305@openssh.com, chacha20-poly1305@openssh.com, implicit by cipher, implicit by cipher, none, none

[25.09.2020 12:10:27] Sending Ed25519 kex init

[25.09.2020 12:10:27] Received Ed25519 kex reply

[25.09.2020 12:10:27] Successfully authentified server

[25.09.2020 12:10:27] Sending new keys message

[25.09.2020 12:10:27] Sending userauth service request

[25.09.2020 12:10:27] Received new keys message

[25.09.2020 12:10:27] Received extension info message

[25.09.2020 12:10:27] Server accepts public key types: ssh-ed25519,ssh-rsa,rsa-sha2-256,rsa-sha2-512,ssh-dss,ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521

[25.09.2020 12:10:27] Received service accepted message

[25.09.2020 12:10:27] Sending userauth init request

[25.09.2020 12:10:27] Received userauth failure: publickey,password,keyboard-interactive

[25.09.2020 12:10:27] Starting interactive authentication

[25.09.2020 12:10:27] Sending userauth interactive request

[25.09.2020 12:10:27] Received userauth failure: publickey,password,keyboard-interactive

[25.09.2020 12:10:27] Starting interactive authentication

[25.09.2020 12:10:27] Sending userauth interactive request

[25.09.2020 12:10:27] Received userauth failure: publickey,password,keyboard-interactive

[25.09.2020 12:10:27] Starting interactive authentication

[25.09.2020 12:10:27] Sending userauth interactive request

[25.09.2020 12:10:27] Received userauth failure: publickey,password,keyboard-interactive

[25.09.2020 12:10:27] Starting interactive authentication

[25.09.2020 12:10:27] Sending userauth interactive request

[25.09.2020 12:10:27] Received userauth failure: publickey,password,keyboard-interactive

[25.09.2020 12:10:27] Starting interactive authentication

[25.09.2020 12:10:27] Sending userauth interactive request

[25.09.2020 12:10:27] Received userauth failure: publickey,password,keyboard-interactive

[25.09.2020 12:10:27] Starting interactive authentication

[25.09.2020 12:10:27] Sending userauth interactive request

[25.09.2020 12:10:27] Received disconnection message, code: 2

[25.09.2020 12:10:27] Too many authentication failures

[25.09.2020 12:10:27] Disconnection in progress

[25.09.2020 12:10:27] Disconnecting