openssh

locked out of my server Permission denied (publickey)

locked out of my server Permission denied (publickey) I was connected to my server. i edited the /root/.ssh/authorized_keys and added —-BEGIN RSA PRIVATE KEY—–at the start of the public key and —–END RSA PRIVATE KEY—–at the end of the public key. I mistakenly lost connection to the host and now despite having id_rsa file, i …

Total answers: 1

How to disable ChaCha20-Poly1305 encryption to stop the terrapin ssh attack

How to disable ChaCha20-Poly1305 encryption to stop the terrapin ssh attack How to disable ChaCha20-Poly1305 encryption from ssh under Debian? I tried (as root): echo ‘Ciphers -chacha20-poly1305@openssh.com’ > /etc/ssh/sshd_config.d/anti-terrapin-attack echo ‘Ciphers -chacha20-poly1305@openssh.com’ > /etc/ssh/ssh_config.d/anti-terrapin-attack systemctl restart sshd But my ssh -Q cipher is still showing chacha20-poly1305@openssh.com. UPDATE: As the answers to fully solving my question …

Total answers: 6

How do you mitigate the Terrapin SSH attack?

How do you mitigate the Terrapin SSH attack? The Terrapin Attack on SSH details a "prefix truncation attack targeting the SSH protocol. More precisely, Terrapin breaks the integrity of SSH’s secure channel. By carefully adjusting the sequence numbers during the handshake, an attacker can remove an arbitrary amount of messages sent by the client or …

Total answers: 2

sFTP admin permission denied when placing files into user directory

sFTP admin permission denied when placing files into user directory I am running Ubuntu 22.04.3 with an sFTP server configured through SSHD. I have several user home directories each with a dropoff and a pickup folder inside of them. While my admin user is able to navigate the server and view the contents of any …

Total answers: 1

Secure remote copy with exceptions

Secure remote copy with exceptions In order to use some data that are stored and produced remotely I first download them via scp servername:/…/big_directory/* ~/. There are many files and the command includes everything. These files change unpredictably (for me), however it’s just a few (over MANY) that actually change between a download and the …

Total answers: 1

what is the use of setting up OpenSSH on Ubuntu Live Server 22.04?

what is the use of setting up OpenSSH on Ubuntu Live Server 22.04? Setup Info I am using Hyper-V to spawn Ubuntu live 22.04 VMs. During the installation procedure it asks if I want to Install OpenSSH server, whether I select this option only results in one change. The change: Cloud init creates a conf …

Total answers: 1

Log in to remote server by using a generated public key

Log in to remote server by using a generated public key I have a zsh script with which I logged into a remote host to copy some folders. The system asks me each time to give the password of the local host which I want to bypass, otherwise I have to enter the passphrase many …

Total answers: 1

can not setup passwordless ssh using key by MANUALLY COPY public key to server

can not setup passwordless ssh using key by MANUALLY COPY public key to server context: firstly, i got a new ubuntu 20.04 server with a password I’m using OpenSSH client on Windows 10 I want to do passwordless login, then I ssh to server using passwords, manually create ~/.ssh /authorized_keys and open it in vim …

Total answers: 1

Are all Debian 11 systems automatically vulnerable to CVE-2023-38408?

Are all Debian 11 systems automatically vulnerable to CVE-2023-38408? I really really hope I’m wrong here, but it seems that Debian 11 has a vulnerable version of OpenSSH. My OpenSSH banner reports my OpenSSH version is: 8.4p1 Debian 5+deb11u1 I checked with sshd and it reports the same version. According to this CVE-2023-38408 ANY version …

Total answers: 1

how to properly mask ssh server background service

how to properly mask ssh server background service I want to mask ssh so the ssh server is disabled till I need it myself. but still want to have ssh client capabilities. I use openssh and the service is ssh.service and its alias sshd.service I use ubuntu 22.04 is the correct steps: systemctl stop sshd …

Total answers: 1

Does ssh client interfere with named pipes?

Does ssh client interfere with named pipes? Setup: I have a system in bash where I have a single file that spawns off a pipeline of background processes. In stage one of the pipeline, there are multiple processes writing to a single named pipe. In the next stage of the pipeline there is a reader …

Total answers: 1

How to make a script to forward commands to an SSH server?

How to make a script to forward commands to an SSH server? I have a remote SSH server with several custom utilities for my work. However, there are times when I feel lazy and don’t want to start a full SSH session just to execute a single command. This motivated me to create a multi-call …

Total answers: 1

How to access my computer's terminal in the university dorm from another computer?

How to access my computer's terminal in the university dorm from another computer? I have used ssh to access remote computers/servers where they provided me a username, a password, and an IP address (like xxx:xxx:xx.xx). What I need to do is: ssh username@xxx.xxx.xx.xx and then it will ask for the password. After entering the password, …

Total answers: 3

Future Security Update to openssh-server on Ubuntu Server 20.04 LTS?

Future Security Update to openssh-server on Ubuntu Server 20.04 LTS? As per: https://launchpad.net/ubuntu/focal/+source/openssh/+changelog and https://ubuntu.com/blog/what-is-an-ubuntu-lts-release and https://ubuntu.com/about/release-cycle " For each Ubuntu LTS release, Canonical maintains the Base Packages and provides security updates, including kernel livepatching, for a period of ten years. " Ubuntu 20.04 LTS was released on April 23, 2020. Will Ubuntu 20.04 LTS …

Total answers: 1

How to restart sshd after assembly?

How to restart sshd after assembly? it is necessary to update the openssh server to the latest version, since everything is closed, it has come to manually assemble it ./configure –prefix=/usr –with-pam –with-selinux –with-privsep-path=/var/lib/sshd/ –with-kerberos5=/etc/krb5.conf –sysconfdir=/etc/ssh –with-default-path=/usr/bin –with-pid-dir=/run && make the version was updated, the installation was successful, but I can’t restart it I get …

Total answers: 1

Why does ssh port forwarding fail?

Why does ssh port forwarding fail? In this example: $ ssh -L 8001:192.168.122.4:80 the output give is the default help: usage: ssh [-46AaCfGgKkMNnqsTtVvXxYy] [-B bind_interface] [-b bind_address] [-c cipher_spec] [-D [bind_address:]port] [-E log_file] [-e escape_char] [-F configfile] [-I pkcs11] [-i identity_file] [-J [user@]host[:port]] [-L address] [-l login_name] [-m mac_spec] [-O ctl_cmd] [-o option] [-p port] …

Total answers: 1

Meaning of "key options: agent-forwarding" in OpenSSH logging

Meaning of "key options: agent-forwarding" in OpenSSH logging At first, I’d like to note that I am aware that there are a lot of other questions regarding SSH agent forwarding. The people there wanted to know how to make agent forwarding work or how to configure it securely. But I have the opposite problem: It …

Total answers: 1