under some kind of attack

mj lists at merit.unu.edu
Tue Jul 18 23:53:40 EEST 2017


Hi Robert,

On 07/18/2017 10:15 PM, mj wrote:
> Robert, your iptables suggestions are _very_ interesting! However, will 
> they also work on imaps/993, because of the ssl?

I have adjusted and put into place your iptables suggestion like this:
> iptables -I INPUT -p tcp --dport 143 -m string --algo bm --string '1q2w3e4r' -j DROP
> iptables -I INPUT -p tcp --dport 993 -m string --algo bm --string '1q2w3e4r' -j DROP

However, I don't think it's working, as the login attempts just keep 
coming. Probably the reason is: smtp is plain text, and imap TLS/SSL is 
not, so the rules never get triggered.

MJ


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