User account security, SSH hardening, and basic system hardening practices for Linux servers.
35 cards · basic cards · AI-written, checked twice. Edit anything.
- What file stores user passwords with their hashes in Linux?
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/etc/shadow- What command is used to safely edit the sudoers file?
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visudo- What are the correct permissions for a private SSH key file?
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600- What SSH configuration option disables root login?
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PermitRootLogin no- What command generates a new SSH key pair?
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ssh-keygen- What SSH configuration option disables password-based authentication?
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PasswordAuthentication no- What is the primary advantage of SSH key-based authentication over passwords?
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Cryptographic keys are more resistant to brute-force attacks and are stronger- What file contains the list of authorized public keys for SSH access?
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~/.ssh/authorized_keys- What does umask control in file permissions?
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Default permissions applied to newly created files and directories- What command sets password aging policies on a user account?
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chage- What is the default SSH configuration file location?
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/etc/ssh/sshd_config- What SSH configuration option limits the number of failed login attempts?
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MaxAuthTries- What happens when a user account reaches its expiration date?
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The account is locked and the user cannot log in- What file lists all user accounts on a Linux system?
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/etc/passwd- What permissions should the /etc/shadow file have?
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600 or 000, readable only by root
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