[SOLVED] ssh connectivity issues

1s440 · 08-12-2022, 06:28 AM

Hi all,

when i tried to connect via ssh, then i get the below error

Code:

Unable to negotiate port 22: no matching cipher found. Their offer: 3des-cbc

If i pass ciphers to the ssh command then I get

Code:

Received disconnect port 22:2:  Client Disconnect

Can anyone suggests?

suramya · 08-12-2022, 06:33 AM

The *-cbc protocols have a vulnerability in them and the recent versions of SSH reject them by default.
You can try the workaround as per https://unix.stackexchange.com/quest...-rejecting-cbc but I would suggest that you upgrade the SSH version of the server as soon as possible.

- Suramya

elgrandeperro · 08-12-2022, 09:11 AM

On the server side, you can set the ciphers in /etc/ssh/ssshd_config:

Ciphers aes128-ctr,aes192-ctr,aes256-ctr,aes128-cbc,3des-cbc,aes192-cbc,aes256-cbc

And you can not ask for that cipher, depending on client.

Turbocapitalist · 08-12-2022, 09:12 AM

Quote:

Originally Posted by 1s440

Can anyone suggests?

Suggestion: Update the server post haste.

sundialsvcs · 08-17-2022, 08:56 PM

Quote:

Originally Posted by Turbocapitalist

Suggestion: Update the server post haste.

Entirely agree. The server appears to be offering to conduct the conversation using a cipher that is considerably out-of-date by present standards. But also, be sure that the client is also as up-to-date as possible. Both parties need to always be "singing from the latest songbook."