Network/SecuringSSH. Top 20 OpenSSH Server Best Security Practices. OpenSSH is the implementation of the SSH protocol.
OpenSSH is recommended for remote login, making backups, remote file transfer via scp or sftp, and much more. SSH is perfect to keep confidentiality and integrity for data exchanged between two networks and systems. However, the main advantage is server authentication, through the use of public key cryptography. From time to time there are rumors about OpenSSH zero day exploit. Here are a few things you need to tweak in order to improve OpenSSH server security. Default Config Files and SSH Port /etc/ssh/sshd_config - OpenSSH server configuration file. SSH Session in Action #1: Disable OpenSSH Server Workstations and laptop can work without OpenSSH server. . #2: Only Use SSH Protocol 2 SSH protocol version 1 (SSH-1) has man-in-the-middle attacks problems and security vulnerabilities.
Protocol 2 #3: Limit Users' SSH Access By default all systems user can login via SSH using their password or public key. AllowUsers root vivek jerry IgnoreRhosts yes. 5 Best Practices to Secure and Protect SSH Server. SSH (Secure Shell) is an open source network protocol that is used to connect local or remote Linux servers to transfer files, make remote backups, remote command execution and other network related tasks via scp or sftp between two servers that connects on secure channel over the network. In this article, I will show you some simple tools and tricks that will help you to tighten your ssh server security. Here you will find some useful information on how to secure and prevent ssh server from brute force and dictionary attacks. 1.
DenyHosts DenyHosts is an open source log-based intrusion prevention security script for SSH servers was written in python programming language that intended to run by Linux system administrators and users to monitor and analyzes SSH server access logs for failed login attempts knows as dictionary based attacks and brute force attacks. DenyHosts Features Read More : Install DenyHosts to Block SSH Server Attacks in RHEL / CentOS / Fedora. Advanced SSH security tips and tricks. The SSH server configuration file is located in /etc/ssh/sshd_conf.
You need to restart the SSH service after every change you make to that file in order for changes to take effect. Change SSH listening port By default, SSH listens for connections on port 22. Attackers use port scanner software to see whether hosts are running an SSH service. It's wise to change the SSH port to a number higher than 1024 because most port scanners (including nmap) by default don't scan high ports. Open the /etc/ssh/sshd_config file and look for the line that says: Port 22 Change the port number and restart the SSH service: /etc/init.d/ssh restart Allow only SSH protocol 2 There are two versions of the SSH protocol.
Protocol 2,1 Change the line so it says only protocol 2. Allow only specific users to log in via SSH You should not permit root logins via SSH, because this is a big and unnecessary security risk. PermitRootLogin yes Change yes to no and restart the service. AllowUsers anze dasa kimy Restart the service.