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FTP Server Hardening Techniques

Comprehensive FTP Server Hardening Techniques

Implement these hardening techniques to secure your FTP servers against vulnerabilities detectable by NetExec and other security assessment tools.

Strong Authentication Measures
FTP Authentication - NetExec Tutorial
  • Implement strong password policies:

    Enforce complex passwords with a minimum length of 12 characters, including uppercase and lowercase letters, numbers, and special characters.

    # Example PAM configuration for password complexity
    password requisite pam_cracklib.so retry=3 minlen=12 dcredit=-1 ucredit=-1 ocredit=-1 lcredit=-1
  • Use SSH key-based authentication for SFTP:

    Configure SFTP to use SSH keys instead of passwords for stronger authentication.

    # In sshd_config
    PasswordAuthentication no
    PubkeyAuthentication yes
  • Implement multi-factor authentication (MFA):

    Use tools like Google Authenticator or YubiKey to add an extra layer of security.

    # Install Google Authenticator PAM module
    sudo apt-get install libpam-google-authenticator
    
    # Configure PAM to use Google Authenticator
    auth required pam_google_authenticator.so
  • Disable anonymous FTP access:

    Unless absolutely necessary, disable anonymous access to prevent unauthorized users from accessing your FTP server.

    # In vsftpd.conf
    anonymous_enable=NO

To test these authentication measures using NetExec, you can use the following command:

netexec ftp 192.168.1.100 -u users.txt -p passwords.txt

This command attempts to brute-force FTP credentials, which should be unsuccessful if strong authentication measures are in place.

For more information on securing file transfers and testing FTP servers with NetExec, check out our File Transfer Security Comparison and FTP Protocol Guide.

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