RE: iptables and apt-get

[Jones, Steven]

I'd put the default INPUT policy last.   here is mine   note some of this is experimental as per my notes in the file.   #!/bin/bash #iptables firewall script #17/06/01 #14/5/02 flushing and prerouting logs added, other rules added but not #27/9/2002 mods for wireless laptop and 3 nics active #8/12/2002 wi-fi working mk1 #start ip_forwarding in /etc/network/options #elvis firewall 19/12/2002 # rules below to be tested # Disable response to ping. #/bin/echo "1" > /proc/sys/net/ipv4/icmp_echo_ignore_all # Disable response to broadcasts. # You don't want yourself becoming a Smurf amplifier. #/bin/echo "1" > /proc/sys/net/ipv4/icmp_echo_ignore_broadcasts   # network. Source routing is rarely used for legitimate purposes. #/bin/echo "0" > /proc/sys/net/ipv4/conf/all/accept_source_route   # Disable ICMP redirect acceptance. ICMP redirects can be used to alter # your routeing tables, possibly to a bad end. #/bin/echo "0" > /proc/sys/net/ipv4/conf/all/accept_redirects # Enable bad error message protection. #/bin/echo "1" > /proc/sys/net/ipv4/icmp_ignore_bogus_error_responses   #These 3 lines below allow flushing without a #reBoot.   iptables -F iptables -X iptables -Z echo "flushed rules"   #set constants outer_nic="eth0" #wifi_nic1="eth1" #inner_nic2="eth2" inner_nic1="eth1" #wifiipsec="ipsec0" #wifi_nw1="172.31.0.0/16" echo "firewall constants setup" #load any modules needed for connection tracking #allow passive ftp /sbin/modprobe ip_conntrack_ftp echo "started connection tracking"   #individual port forwarding echo "no portfw started"   #post routeing rules #iptables -t nat -A POSTROUTING -s $wifi_nw1 -o $outer_nic -j MASQUERADE #iptables -t nat -A POSTROUTING -o $outer_nic -j MASQUERADE #iptables -t nat -A POSTROUTING -s $wifi_nw2 -o $outer_nic -j MASQUERADE #iptables -t nat -A POSTROUTING -s $wifi_nw2 -d 0.0.0.0/0 -j MASQUERADE #iptables -t nat -A POSTROUTING -s $wifi_nw1 -o inner_nic2 \ #-j MASQUERADE   #forward rules #iptables -A FORWARD -i $wifi_nic1 -j DROP #iptables -A FORWARD -i $wifi_nic1 -j ACCEPT #iptables -A FORWARD -i $wifiipsec -j ACCEPT #iptables -A FORWARD -i $inner_nic2 -j ACCEPT #iptables -A FORWARD -m state --state ESTABLISHED,RELATED -j ACCEPT iptables -P FORWARD DROP #echo "FORWARD rules in place" echo "no FORWARD rules in place"   #INPUT rules #specific ipsec lines #iptables -A INPUT -p udp --dport 500 -j ACCEPT #iptables -A INPUT -p 50 -j ACCEPT #iptables -A INPUT -p 51 -j ACCEPT #echo "IPSEC rules now in place" echo "IPSEC rules not activated" #general iptables -A INPUT -p tcp --dport 22 -j ACCEPT iptables -A INPUT -p tcp --dport 21 -j ACCEPT iptables -A INPUT -p udp --dport 21 -j ACCEPT #smb iptables -A INPUT -p udp --dport 137 -j ACCEPT #iptables -A INPUT -p tcp --dport 137 -j ACCEPT iptables -A INPUT -p udp --dport 138 -j ACCEPT iptables -A INPUT -p tcp --dport 138 -j ACCEPT iptables -A INPUT -p udp --dport 139 -j ACCEPT iptables -A INPUT -p tcp --dport 139 -j ACCEPT #web iptables -A INPUT -p tcp --dport 80 -j ACCEPT iptables -A INPUT -p tcp --dport 443 -j ACCEPT #x11 drop iptables -A INPUT  -p udp --dport 6000:6009 -j DROP iptables -A INPUT  -p tcp --dport 6000:6009 -j DROP #specific worm / problem blocking iptables -A INPUT  -p tcp --dport 23 -j DROP iptables -A INPUT  -p tcp --dport 25 -j DROP iptables -A INPUT  -p tcp --dport 53 -j DROP iptables -A INPUT  -p udp --dport 53 -j DROP iptables -A INPUT  -p tcp --dport 135 -j DROP iptables -A INPUT  -p tcp --dport 445 -j DROP iptables -A INPUT  -p tcp --dport 1080 -j DROP iptables -A INPUT  -p tcp --dport 1214 -j DROP iptables -A INPUT  -p tcp --dport 1433 -j DROP iptables -A INPUT  -p tcp --dport 1434 -j DROP iptables -A INPUT  -p tcp --dport 1080 -j DROP   #iptables -A INPUT -s $wifi_nw1 -p tcp --syn --dport 22 -j ACCEPT #iptables -A INPUT -i $wifi_nic1 -p TCP --destination-port 22 -j ACCEPT #iptables -A INPUT -s $inner_fw -p tcp --syn --dport 22 -j ACCEPT iptables -A INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT iptables -A INPUT -m state --state NEW -i ! $outer_nic -j ACCEPT #iptables -A INPUT -i $wifiipsec -j ACCEPT   #allow ping replies (may not be desired) #iptables -A INPUT -p icmp -s 0/0 --icmp-type echo-request -j ACCEPT #me playing below with icmp iptables -A INPUT -p icmp -s 0/0 --icmp-type 0 -j ACCEPT iptables -A INPUT -p icmp -s 0/0 --icmp-type 3 -j ACCEPT iptables -A INPUT -p icmp -s 0/0 --icmp-type 4 -j ACCEPT iptables -A INPUT -p icmp -s 0/0 --icmp-type 5 -j ACCEPT iptables -A INPUT -p icmp -s 0/0 --icmp-type 8 -j ACCEPT iptables -A INPUT -p icmp -s 0/0 --icmp-type 11 -j ACCEPT #to be tested #iptables -A INPUT -i $IFACE -f -j LOG --log-prefix "IPTABLES FRAGMENTS: #" #iptables -A INPUT -i $outer_nic -f -j DROP   iptables -P INPUT DROP echo "INPUT rules now in place"   #output tables are default #echo "output rules now in place" #limit logging levels to save clutter and /var from being swamped iptables -A FORWARD -m limit -j LOG echo "log limiting in place"   #specific defence rules eg DoS attacks #syn-flood protection iptables -A FORWARD -p tcp --syn -m limit --limit 1/s -j ACCEPT #furtive port scanner iptables -A FORWARD -p tcp --tcp-flags SYN,ACK,FIN,RST RST -m limit \ --limit 1/s -j ACCEPT #ping of death iptables -A FORWARD -p icmp --icmp-type echo-request -m limit \ --limit 1/s -j ACCEPT echo "DoS defences setup"   exit regards Thing -----Original Message----- From: Ian Goodall [mailto:[EMAIL PROTECTED] Sent: Tuesday, 11 March 2003 2:21 To: Jones, Steven; debian-security@lists.debian.org Subject: Re: iptables and apt-get Here is my rule set:     #default input policy /sbin/iptables -P INPUT DROP #allow www/https(ssl) /sbin/iptables -A INPUT -s 0/0 -d 172.16.5.92 -p tcp --dport https -j ACCEPT #allow ssh /sbin/iptables -A INPUT -s 0/0 -d 172.16.5.92 -p tcp --dport ssh -j ACCEPT #allow smtp /sbin/iptables -A INPUT -s 0/0 -d 172.16.5.92 -p tcp --dport smtp -j ACCEPT   #create a new rule for drop # log #/sbin/iptables -N drop-and-log-it #log it #/sbin/iptables -A drop-and-log-it -j LOG --log-level info --log-prefix 'DROPIT' #drop it #/sbin/iptables -A drop-and-log-it -j DROP   #now call the rule to drop and log   /sbin/iptables -A INPUT -j drop-and-log-it     ----------- Thanks   ijg0 ----- Original Message ----- From: Jones, Steven To: 'Ian Goodall' ; debian-security@lists.debian.org Sent: Tuesday, March 11, 2003 1:11 AM Subject: RE: iptables and apt-get shouldnt do   unless you changed the output rules?   please provide your ruleset   Thing -----Original Message----- From: Ian Goodall [mailto:[EMAIL PROTECTED] Sent: Tuesday, 11 March 2003 2:06 To: debian-security@lists.debian.org Subject: iptables and apt-get Hi Guys,   I am setting up iptables on my debain woody box. I have decided to close everyting and then open up just ssh and ssl. This obviously prevents my apt-get update from working. What ports do I need to open for this to work. If it helps I am going through a proxy to get to the internet.   Thanks   ijg0