Filtered address in can login

Nikolai Alexandrov voyager123bg at gmail.com
Tue Aug 16 19:34:59 CEST 2005


Are you sure your default POLICIES are ok? I mean...
do you have somewhere:
iptables -P INPUT DROP
iptables -P FORWARD DROP
iptables -P OUTPUT DROP
... your script ...
iptables -A OUTPUT -p tcp -m state --state NEW,ESTABLISHED,RELATED -j ACCEPT

You should also consider adding rules for the DNS to work.


vladimir wrote:

>Hi, I have iptables-1.2.7a and 2.4.26 kernel and there is something
>strange.
>I have the following rule:
>iptables -A INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT
>iptables -A INPUT -s 0/0 --protocol tcp --destination-port 80 -j ACCEPT
>iptables -A INPUT -s IP_ADDR  --protocol tcp --destination-port 22  -j
>ACCEPT
>iptables -A INPUT -p tcp --syn -j DROP
>
>So I expect that only  the specified IP_ADDR can ssh to port 22 in my
>server.
>But in /var/log/secure I see that some other IP's for example
>168.179.113.141 try to login to ssh  with different user names to my
>server.
>However, then I try ssh to that server not from IP_ADDR I can not, as
>expected.
>Please tell me how this 168.179.113.141 bypass my firewall.
>Thank you very much, 
>Vladimir
>  
>



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