Re: [Full-disclosure] targetted SSH bruteforce attacks

[John Jacobs <flamdugen@xxxxxxxxxxx>]

> > Of course it's wise to disable password authentication and just use
> > public key authentication.
> 
> Why?  Ssh is encrypted, so you're not exposing a password when you login.  
> How 
> does public key authentication make you more secure (in a practical sense)?
> 

Paul, it's more secure in that brute force attacks are mitigated because the 
private key is required by the client and the public key must appear in 
~/.ssh/authorized_keys.  Disabling password authentication means a weak 
password on an account cannot be compromised by brute force or other discovery 
efforts.  A password on the private key provides even greater defense-in-depth 
security.

Disable password authentication and enforce key-pair authentication and 
targeted brute-force attacking becomes moot very quickly.  Moving SSHd from TCP 
22 also keeps the script-kiddies and automated scanners away.

After doing these two basic things then it's time to focus on fail2ban, 
denyhosts, and the other firewall integrating solutions.


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