#
|
# /etc/bastille-firewall.cfg
|
#
|
# Configuration file for both 2.2/ipchains and 2.4/netfilter scripts
|
#
|
# $Source: /cvsroot/bastille-linux/dev/working_tree/Bastille/bastille-firewall.cfg,v $
|
# Modified by: $Author: peterw $
|
# $Date: 2002/01/04 13:34:18 $
|
# $Revision: 1.7 $
|
#
|
# Copyright (C) 1999-2001 Peter Watkins
|
#
|
# This program is distributed in the hope that it will be useful,
|
# but WITHOUT ANY WARRANTY; without even the implied warranty of
|
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
# GNU General Public License for more details.
|
#
|
# You should have received a copy of the GNU General Public License
|
# along with this program; if not, write to the Free Software
|
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
|
#
|
# Thanks to David Ranch, Brad A, Don G, and others for their suggestions
|
|
# the configuration values should be whitespace-delimited lists of
|
# appropriate values, e.g.
|
# TCP_PUBLIC_SERVICES="80 smtp ssh"
|
# lists Web (port 80), SMTP mail, and Secure Shell ports
|
#
|
# This script is suitable for workstations or simple NAT firewalls;
|
# you may want to add more "output" restrictions for serious servers
|
|
# 0) DNS servers (Linux 2.2/ipchains only)
|
# You must list your DNS servers here so that
|
# the firewall will allow them to service your lookup requests
|
#
|
# List of DNS servers/networks to allow "domain" responses from
|
# This _could_ be nameservers as a list of <ip-address>/32 entries
|
#DNS_SERVERS="a.b.c.d/32 e.f.g.h/32"
|
# If you are running a caching nameserver, you'll need to allow from
|
# "0.0.0.0/0" so named can query any arbitrary nameserver
|
# (To enable a caching nameserver, you will also probably need to
|
# add "domain" to the TCP and UDP public service lists.)
|
#DNS_SERVERS="0.0.0.0/0"
|
#
|
# To have the DNS servers parsed from /etc/resolv.conf at runtime,
|
# as normal workstations will want, make this variable empty
|
#DNS_SERVERS=""
|
#
|
# Please make sure variable assignments are on single lines; do NOT
|
# use the "\" continuation character (so Bastille can change the
|
# values if it is run more than once)
|
DNS_SERVERS="{DNS_SERVERS}"
|
|
|
# 1) define your interfaces (all systems)
|
# Note a "+" acts as a wildcard, e.g. ppp+ would match any PPP
|
# interface
|
#
|
# list internal/trusted interfaces
|
# traffic from these interfaces will be allowed
|
# through the firewall, no restrictions
|
#TRUSTED_IFACES="lo" # MINIMAL/SAFEST
|
#
|
# list external/untrusted interfaces
|
#PUBLIC_IFACES="eth+ ppp+ slip+" # SAFEST
|
#
|
# list internal/partially-trusted interfaces
|
# e.g. if this acts as a NAT/IP Masq server and you
|
# don't want clients on those interfaces having
|
# full network access to services running on this
|
# server (as the TRUSTED_IFACES allows)
|
#INTERNAL_IFACES="" # SAFEST
|
#
|
# Please make sure variable assignments are on single lines; do NOT
|
# use the "\" continuation character (so Bastille can change the
|
# values if it is run more than once)
|
TRUSTED_IFACES="lo" # MINIMAL/SAFEST
|
PUBLIC_IFACES="eth+ ppp+ slip+ venet+ bond+ en+" # SAFEST
|
INTERNAL_IFACES="" # SAFEST
|
|
|
# 2) services for which we want to log access attempts to syslog (all systems)
|
# Note this only audits connection attempts from public interfaces
|
#
|
# Also see item 12, LOG_FAILURES
|
#
|
#TCP_AUDIT_SERVICES="telnet ftp imap pop3 finger sunrpc exec login linuxconf ssh"
|
# anyone probing for BackOrifice?
|
#UDP_AUDIT_SERVICES="31337"
|
# how about ICMP?
|
#ICMP_AUDIT_TYPES=""
|
#ICMP_AUDIT_TYPES="echo-request" # ping/MS tracert
|
#
|
# To enable auditing, you must have syslog configured to log "kern"
|
# messages of "info" level; typically you'd do this with a line in
|
# syslog.conf like
|
# kern.info /var/log/messages
|
# though the Bastille port monitor will normally want these messages
|
# logged to a named pipe instead, and the Bastille script normally
|
# configures syslog for "kern.*" which catches these messages
|
#
|
# Please make sure variable assignments are on single lines; do NOT
|
# use the "\" continuation character (so Bastille can change the
|
# values if it is run more than once)
|
#TCP_AUDIT_SERVICES="telnet ftp imap pop3 finger sunrpc exec login linuxconf ssh"
|
#UDP_AUDIT_SERVICES="31337"
|
#ICMP_AUDIT_TYPES=""
|
|
|
# 3) services we allow connections to (all systems)
|
#
|
# FTP note:
|
# To allow your machine to service "passive" FTP clients,
|
# you will need to make allowances for the passive data
|
# ports; Bastille users should read README.FTP for more
|
# information
|
#
|
# "public" interfaces:
|
# TCP services that "public" hosts should be allowed to connect to
|
#TCP_PUBLIC_SERVICES="" # MINIMAL/SAFEST
|
#
|
# UDP services that "public" hosts should be allowed to connect to
|
#UDP_PUBLIC_SERVICES="" # MINIMAL/SAFEST
|
#
|
# "internal" interfaces:
|
# (NB: you will need to repeat the "public" services if you want
|
# to allow "internal" hosts to reach those services, too.)
|
# TCP services that internal clients can connect to
|
#TCP_INTERNAL_SERVICES="" # MINIMAL/SAFEST
|
#
|
# UDP services that internal clients can connect to
|
#UDP_INTERNAL_SERVICES="" # MINIMAL/SAFEST
|
#
|
# Please make sure variable assignments are on single lines; do NOT
|
# use the "\" continuation character (so Bastille can change the
|
# values if it is run more than once)
|
TCP_PUBLIC_SERVICES="{tmpl_var name="TCP_PUBLIC_SERVICES"}" # MINIMAL/SAFEST
|
UDP_PUBLIC_SERVICES="{tmpl_var name="UDP_PUBLIC_SERVICES"}" # MINIMAL/SAFEST
|
TCP_INTERNAL_SERVICES="" # MINIMAL/SAFEST
|
UDP_INTERNAL_SERVICES="" # MINIMAL/SAFEST
|
|
# 4) passive/active FTP (Linux 2.2/ipchains only)
|
# FTP is a firewall nightmare; if you allow "normal" FTP connections,
|
# you must be careful to block any TCP services that are listening
|
# on high ports; it's safer to require your FTP clients to use
|
# "passive" mode.
|
#
|
# Note this will also force clients on machines
|
# that use this one for NAT/IP Masquerading to use passive mode
|
# for connections that go through this server (e.g. from the
|
# internal network to public Internet machines
|
#
|
# For more information about FTP, see the Bastille README.FTP doc
|
#
|
#FORCE_PASV_FTP="N"
|
#FORCE_PASV_FTP="Y" # SAFEST
|
#
|
FORCE_PASV_FTP="Y" # SAFEST
|
|
|
# 5) Services to explicitly block. (Linux 2.2/ipchains only)
|
# See FTP note above
|
# Note that ranges of ports are specified with colons, and you
|
# can specify an open range by using only one number, e.g.
|
# 1024: means ports >= 1024 and :6000 means ports <= 6000
|
#
|
# TCP services on high ports that should be blocked if not forcing passive FTP
|
# This should include X (6000:6010) and anything else revealed by 'netstat -an'
|
# (this does not matter unless you're not forcing "passive" FTP)
|
#TCP_BLOCKED_SERVICES="6000:6020"
|
#
|
# UDP services to block: this should be UDP services on high ports.
|
# Your only vulnerability from public interfaces are the DNS and
|
# NTP servers/networks (those with 0.0.0.0 for DNS servers should
|
# obviously be very careful here!)
|
#UDP_BLOCKED_SERVICES="2049"
|
#
|
# types of ICMP packets to allow
|
#ICMP_ALLOWED_TYPES="destination-unreachable" # MINIMAL/SAFEST
|
# the following allows you to ping/traceroute outbound
|
#ICMP_ALLOWED_TYPES="destination-unreachable echo-reply time-exceeded"
|
#
|
# Please make sure variable assignments are on single lines; do NOT
|
# use the "\" continuation character (so Bastille can change the
|
# values if it is run more than once)
|
TCP_BLOCKED_SERVICES="6000:6020"
|
UDP_BLOCKED_SERVICES="2049"
|
ICMP_ALLOWED_TYPES="destination-unreachable echo-reply time-exceeded echo-request"
|
|
|
# 6) Source Address Verification (all Linux systems)
|
# This helps prevent "IP Spoofing" attacks
|
#
|
ENABLE_SRC_ADDR_VERIFY="Y" # SAFEST
|
|
|
# 7) IP Masquerading / NAT. (all systems)
|
# List your internal/masq'ed networks here
|
#
|
# Also see item 4, FORCE_PASV_FTP, as that setting affects
|
# clients using IP Masquerading through this machine
|
#
|
# Set this variable if you're using IP Masq / NAT for a local network
|
#IP_MASQ_NETWORK="" # DISABLE/SAFEST
|
#IP_MASQ_NETWORK="10.0.0.0/8" # example
|
#IP_MASQ_NETWORK="192.168.0.0/16" # example
|
#
|
# Have lots of masq hosts? uncomment the following six lines
|
# and list the hosts/networks in /etc/firewall-masqhosts
|
# the script assumes any address without a "/" netmask afterwards
|
# is an individual address (netmask /255.255.255.255):
|
#if [ -f /etc/firewall-masqhosts ]; then
|
# echo "Reading list of masq hosts from /etc/firewall-masqhosts"
|
# # Read the file, but use 'awk' to strip comments
|
# # Note the sed bracket phrase includes a space and tab char
|
# IP_MASQ_NETWORK=`cat /etc/firewall-masqhosts | awk -F\# '/\// {print $1; next} /[0-9]/ {print $1"/32"}' |sed 's:[ ]*::g'`
|
#fi
|
#
|
# Masq modules
|
# NB: The script will prepend "ip_masq_" to each module name
|
#IP_MASQ_MODULES="cuseeme ftp irc quake raudio vdolive" # ALL (?)
|
#IP_MASQ_MODULES="ftp raudio vdolive" # RECOMMENDED
|
#
|
# Please make sure variable assignments are on single lines; do NOT
|
# use the "\" continuation character (so Bastille can change the
|
# values if it is run more than once)
|
IP_MASQ_NETWORK="" # DISABLE/SAFEST
|
IP_MASQ_MODULES="ftp raudio vdolive" # RECOMMENDED
|
|
|
# 8) How to react to disallowed packets (all systems)
|
# whether to "REJECT" or "DROP" disallowed packets; if you're running any
|
# public services, you probably ought to use "REJECT"; if in serious stealth
|
# mode, choose "DROP" so simple probes don't know if there's anything out there
|
# NOTE: disallowed ICMP packets are discarded with "DROP", as
|
# it would not make sense to "reject" the packet if you're
|
# trying to disallow ping/traceroute
|
# NOTE: the scripts that set up the filter rules will interpret these
|
# keywords as needed, e.g. "DROP" becomes "DENY" for Linux 2.2/ipchains
|
#
|
REJECT_METHOD="DROP"
|
|
|
# 9) DHCP (Linux 2.2/ipchains only)
|
# In case your server needs to get a DHCP address from some other
|
# machine (e.g. cable modem)
|
#DHCP_IFACES="eth0" # example, to allow you to query on eth0
|
#DHCP_IFACES="" # DISABLED
|
#
|
# Please make sure variable assignments are on single lines; do NOT
|
# use the "\" continuation character (so Bastille can change the
|
# values if it is run more than once)
|
DHCP_IFACES="" # DISABLED
|
|
|
# 10) NTP servers (Linux 2.2/ipchains only)
|
# more UDP fun. List IP addresses or network space of NTP servers
|
#
|
#NTP_SERVERS="" # DISABLE NTP QUERIES / SAFEST
|
#NTP_SERVERS="a.b.c.d/32 e.f.g.h/32" # example, to allow querying 2 servers
|
#
|
# Please make sure variable assignments are on single lines; do NOT
|
# use the "\" continuation character (so Bastille can change the
|
# values if it is run more than once)
|
NTP_SERVERS="" # DISABLE NTP QUERIES / SAFEST
|
|
|
# 11) more ICMP. (Linux 2.2/ipchains only)
|
# Control the outbound ICMP to make yourself invisible to
|
# traceroute probes
|
#
|
#ICMP_OUTBOUND_DISABLED_TYPES="destination-unreachable time-exceeded"
|
#
|
# Please make sure variable assignments are on single lines; do NOT
|
# use the "\" continuation character (so Bastille can change the
|
# values if it is run more than once)
|
ICMP_OUTBOUND_DISABLED_TYPES="destination-unreachable time-exceeded"
|
|
|
# 12) Logging (all systems)
|
# With this enabled, ipchains will log all blocked packets.
|
# ** this could generate huge logs **
|
# This is primarily intended for the port mointoring system;
|
# also note that you probably do not want to "AUDIT" any services
|
# that you are not allowing, as doing so would mean duplicate
|
# logging
|
LOG_FAILURES="N" # do not log blocked packets
|
|
# 13) Block fragmented packets (all systems)
|
# There's no good reason to allow these
|
#ALLOW_FRAGMENTS="N" # safest
|
ALLOW_FRAGMENTS="Y" # old behavior
|
|
# 14) Prevent SMB broadcasts from leaking out NAT setup (all systems)
|
# Windows machines will poll teh net with SMB broadcasts,
|
# basically advertising their existence. Most folks agree
|
# that this traffic should be dropped
|
#DROP_SMB_NAT_BCAST="N" # allow them (are you sure?)
|
DROP_SMB_NAT_BCAST="Y" # drop those packets
|
|
# 15) Log level (iptables/netfilter/Linux 2.4 only)
|
# Control what level of logging is used when the firewall logs
|
# information. Default is warning (4). Lowest priority is
|
# debug (7); highest is emergency (0). To prevent syslog
|
# from copying iptables error messages to the console, set
|
# this to 6 (7 would also work, but 6 is recommended)
|
# You can also stop syslogd/klogd from printing kernel
|
# messages to the console by issuing the command
|
# setterm -msg off
|
#IP_LOG_LEVEL=6 # level used in 2.2/ipchains
|
IP_LOG_LEVEL=4 # iptables/netfilter default
|
|
# 16) Always attempt to use stateful features for inbound connections
|
# Always using state will allow the firewall to reject invalid
|
# packets sent to otherwise open TCP services, e.g. XMAS, NULL
|
# and SIN/FYN scans. The downside to choosing this behavior is that
|
# services may become unreachable if the packet filter's state
|
# table becomes full.
|
IP_ALWAYS_USE_STATE="N" # default, ensures services remain available
|
#IP_ALWAYS_USE_STATE="Y" # disallow invalid packets
|