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17

DD-WRT: Remove SSH login banner

Posted in myDocs, myLinux      3 comments

Despite DD-WRT is a cool firmware there are some default things that looks very crap from a security point of view. One of these is the ssh login banner used by sshd.

To remove it use Web interface > Administration > Commands > paste



echo "Unauthorized access is prohibited." > /tmp/loginprompt
killall dropbear
dropbear -b /tmp/loginprompt -r /tmp/root/.ssh/ssh_host_rsa_key -d /tmp






and press "Save Startup" button.
Power light will blink for 30 seconds. After that sshd will show new banner.

gnuton@iron:~$ ssh root@192.168.1.1
Unauthorized access is prohibited.
root@192.168.1.1's password:

 
		

		
		
		
		
		
		
		
		
		
		
        


	
3 Comments to “DD-WRT: Remove SSH login banner”


	
    
	   
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	   	  February 16, 2010 at 9:16 pm 
    moleary says:	      
	  
    

      
    
		  
    
		  
    
		  
    
		  
    
		  
    
		  
    Just to let you know this doesn’t seem to work for me on version: Release: 01/02/10 (SVN revision: 13575)
    
	  
    
	  
	  
      
    
               
    
     
    

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	   	  February 17, 2010 at 9:58 am 
    gnuton says:	      
	  
    

      
    
		  
    
		  
    
		  
    
		  
    
		  
    
		  
    hi Micheal,
    
It doesn’t work in case the banner is modified after that sshd is started.
    
So after echo “Unauthorized access is prohibited.” > /tmp/loginprompt
    
you could force the sshd to restart.
    
Usually you could do that in Linux with
    
/etc/init.d/sshd restart &
    

    Be careful with startup commands since bad commands can break boot process..
    
	  
    
	  
	  
      
    
               
    
     
    

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	   	  February 21, 2010 at 5:02 pm 
    admin says:	      
	  
    

      
    
		  
    
		  
    
		  
    
		  
    
		  
    
		  
    Post updated… now it works..
    
	  
    
	  
	  
      
    
               
    
     
    

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