Shell security in Linux is a critical aspect of system administration and helps protect the system from unauthorized access and attacks. Here are several key points and practices related to shell security in Linux:
chmod, chown, and chgrp commands to set proper permissions.sudo to grant temporary elevated privileges. Configure /etc/sudoers carefully to control which commands users can execute.rbash) for users who need limited access. Modify users’ default shell in /etc/passwd..bashrc, .bash_profile, and .profile to prevent unauthorized command execution on login.PATH. Ensure they don’t include directories writable by unprivileged users to avoid privilege escalation.secure_path in /etc/sudoers to enforce a secure PATH for sudo commands.HISTCONTROL to ignore duplicate commands and commands that start with space (HISTCONTROL=ignoredups:ignorespace). Secure the command history file (.bash_history) to restrict access.auditd to log shell commands and monitor user activities. Regularly check logs for suspicious activities.set +m) or disabling the ability to execute certain commands through shell options.rbash: The restricted bash shell (rbash) limits certain operations, such as changing directories or setting the PATH.iptables or firewalld) to restrict access to the shell over the network.OSSEC or AIDE to monitor for unauthorized changes and suspicious activities.