# Cleaning up audit logs on solaris
# Source: http://docs.sun.com/app/docs/doc/816-4557/audittask-12?a=view
# List the files with the not_terminated string on your audit file system in order of creation.
ls -R1t audit-directory*/files/* | grep not_terminated
# -R Lists files in subdirectories.,-t Lists files from most recent to oldest.,-1 Lists the files in one column.
# Clean up the old not_terminated file.Specify the name of the old file to the auditreduce -O command.
auditreduce -O system-name old-not-terminated-file
# Remove the old not_terminated file.
rm system-name old-not-terminated-file
# Finding Disk Utilisation
df -k
or
du -sk * |sort -rn | head
or
du -k * |sort -rn | head
# For Solaris servers.To check usage in current filesystem/device
du -dk <filesystem> | sort -rn | head
#eg.
du -dk /opt/sunone61 | sort -rn | head
#For reverse sorting by size
ls -lSr
or
du | sort -nr | cut -f2- | xargs du -hs | head
or
du | sort -nr | cut -f2- | xargs du -s | head
#Find the Top 10 biggest directories under /
du -kod / |sort -n | tail -10
# Reverse sort by change date
ls -ltr
# Finding Directory sizes
du -sh folder_name
du -ch folder_name
du -csh folder_name
# List files and ignore .gz files
ls -lah | grep -v '.gz$'
# Finding files above 100 Mb
find / -type f -size +100000k -exec ls -lh {} \; | awk '{ print $9 ": " $5 }'
find / -type f -size +100000k
# Find 10 largest directores in current directory
du -hs */ | sort -hr | head
# To move files older than 90 days in the current directory and move them to /tmp folder
# in current and sub directories
find . -type f -mtime +90 -exec mv {} /tmp \;
# In current directory only
find . -maxdepth 1 -type f -mtime +90 -exec mv {} /tmp \;
To move *.gz files older than 90 days in the current directory and move them to /tmp folder
find . -type f -mtime +90 -name "*.gz" -exec mv {} /tmp/ \;
# To delete files older than 90 days in the current directory
find . -mtime +90 -exec rm {} \;
# To delete files named core.fmd.* in the current directory
find . -type f -name "core.fmd.*" -exec rm {} \;
# To find all files having log in the file name and older than 30 days in the location /
find / -mtime +30 -type f -name "*.log.*" -exec ls -lh {} \; | awk '{ print $9 ": " $5 }'
# To compress all files having log in the file name and older than 30 days in the location /
find / -mtime +30 -type f -name "*.log.*" -exec gzip {} \;
# Compressing and nullyfying a file in one go
cp -a /<path>/<file_name> /tmp && cat /dev/null > /<path>/<file_name> && gzip /tmp/<file_name> && mv /tmp/<file_name>.gz /<path>
Monday, April 14, 2008
Dealing with large files and directories in Linux/Unix
Thursday, April 03, 2008
Shorewall setup to ease your Iptables setup
Reference:
http://www.shorewall.net/shorewall_setup_guide.htm
# Backup your existing Iptables configuration so that you can revert back in case something goes wrong
cp -a /etc/sysconfig/iptables /etc/sysconfig/iptables_backup_
# Deploying a safety net to ensure that you dont get locked out
Reference : http://www.iptablesrocks.org/guide/safetynet.php
vi /root/firewall_reset
############
# Iptables firewall reset script
*filter
:INPUT ACCEPT [164:15203]
:FORWARD ACCEPT [0:0]
:OUTPUT ACCEPT [147:63028]
COMMIT
*mangle
:PREROUTING ACCEPT [164:15203]
:INPUT ACCEPT [164:15203]
:FORWARD ACCEPT [0:0]
:OUTPUT ACCEPT [147:63028]
:POSTROUTING ACCEPT [147:63028]
COMMIT
*nat
:PREROUTING ACCEPT [14:672]
:POSTROUTING ACCEPT [9:684]
:OUTPUT ACCEPT [9:684]
COMMIT
###########
# Test if the above script works and throws no error
/sbin/iptables-restore < /root/firewall_reset
/sbin/iptables -L
# The output should be similar to the following
###
Chain FORWARD (policy ACCEPT)
target prot opt source destination
Chain INPUT (policy ACCEPT)
target prot opt source destination
Chain OUTPUT (policy ACCEPT)
target prot opt source destination
###
# restore your orginal firewall configuration and proceed
/sbin/iptables-restore < /etc/sysconfig/iptables_backup_
# Confirm that your original rules have been restored by running the following command
/sbin/iptables -L
# Create a crontab entry that resets the firewall every 15 minutes
crontab -e
0,15,30,45 * * * * /sbin/iptables-restore < /root/firewall_reset
# Please ensure that you comment out this line after you have succesfully tested you shorewall working.
# Reference:http://www.shorewall.net/shorewall_quickstart_guide.htm
# Before installing ,check if iproute and shorewall already exist
rpm -qa | grep -i "iproute"
rpm -qa | grep -i "shorewall"
# If iproute doesn't exist then proceed as follows
yum install iproute
# Shorewall Installation
# Using Yum
yum install shorewall
# Using RPM
# In most cases shorewall would not exist in yum repositories so proceed as follows for the rpm installation
References :
http://www.shorewall.net/Install.htm
http://www.shorewall.net/download.htm
Download the shorewall and shorewall-perl rpm package
cd /tmp
wget http://www.invoca.ch/pub/packages/shorewall/4.2/shorewall-4.2.5/shorewall-4.2.5-3.noarch.rpm
wget http://www.invoca.ch/pub/packages/shorewall/4.2/shorewall-4.2.5/shorewall-perl-4.2.5-3.noarch.rpm
rpm -ivh shorewall-perl-4.2.5-3.noarch.rpm shorewall-4.2.5-3.noarch.rpm
#Setting up Shorewall on a standalone Linux system with a single static IP address
Reference :http://www.shorewall.net/standalone.htm
# Add your IP address (IP address of the system/gateway you are connecting from and not the server IP address where you are installing shorewall) to the /etc/shorewall/routestopped file to ensure that you stay connected when the firewall restarts.You can find your IP address by visiting http://whatismyip.com
cp -a /etc/shorewall/routestopped /etc/shorewall/routestopped.orig
vi /etc/shorewall/routestopped
# eg. if your IP address ( the system/gateway you are connecting from) is 59.144.118.69
#INTERFACE HOST(S)
eth0 59.144.0.0/24
# You can also add a CIDR number to indicate a range of IPs from which connection will not break
# For eg. if you want to keep alive connections from 192.168.0.1 to 192.168.0.254 during the firewall restart add the following line
#INTERFACE HOST(S)
eth0 192.168.0.0/24
# Find the sample configuration files by running
rpm -ql shorewall | fgrep one-interface
cp -a /usr/share/doc/shorewall-4.2.5/Samples/one-interface /tmp/
cd /tmp/one-interface
# Confirm your ethernet interface ( to check if you have a single lan card)
/sbin/ifconfig -a
vi interfaces
########
#ZONE INTERFACE BROADCAST OPTIONS
net eth0 210.210.18.90 norfc1918,routefilter,tcpflags,logmartians,nosmurfs
########
# The BROADCAST address can be ignored above and instead you can put a -
#RFC-1918 reserves several Private IP address ranges for use in private networks:
10.0.0.0 - 10.255.255.255
172.16.0.0 - 172.31.255.255
192.168.0.0 - 192.168.255.255
#If your IP address falls in any of the above range, then please remove "norfc1918" in the options section of the interfaces file
# If you have a non-static DHCP IP address,add "detect" in the "broadcast" section and add “dhcp” to the option list.
# Configuration of rules
# You can find custom rules files by running
ls /usr/share/shorewall/macro.*
# You can then use these macros in your shorewall rules file
# For eg. if you want to allow access to your web server running TCP Port 80 and SSHD running on TCP port 22 do the following
# Tip: You can identify the network services running on your server bu issuing the following command.
/bin/netstat -luntp
# Based on the output you get , you can decide which services to allow remote access or not
cd /tmp/one-interface
vi rules
#######
#ACTION SOURCE DESTINATION PROTO DEST PORT(S)
Web/ACCEPT net $FW
SSH/ACCEPT net $FW
######
# You can also add the above rules in this way.
vi rules
#########
#ACTION SOURCE DESTINATION PROTO DEST PORT(S)
ACCEPT net $FW tcp 80
ACCEPT net $FW tcp 22
#########
# You can also add the following rule if you see port TCP 113 as closed in your nmap scan.
DROP net $FW tcp 113
If you want to allow conections to let's say the ssh port only from specific IP Addresses on the internet add the following
ACCEPT net:192.0.2.16/28,192.0.2.44 fw tcp 22
# Please ensure that you check the individual macros you applies from /usr/share/shorewall/macro.* to ensure that they work as desired
# You must enable startup by editing /etc/shorewall/shorewall.conf and setting STARTUP_ENABLED=Yes
cp -a /tmp/one-interface/shorewall.conf /tmp/one-interface/shorewall.conf.orig
vi /tmp/one-interface/shorewall.conf
# Modify the lines as shown
#STARTUP_ENABLED=No
STARTUP_ENABLED=Yes
#IPTABLES=
IPTABLES=/sbin/iptables
#IP_FORWARDING=On
IP_FORWARDING=Off
#DISABLE_IPV6=Yes
# Copy your configuration files to appropriate locations
cd /etc/shorewall/
cp -a policy policy.orig
cp -a rules rules.orig
cp -a interfaces interfaces.orig
cp -a zones zones.orig
cp -a /tmp/one-interface/* /etc/shorewall/
rm -rf /tmp/one-interface/
/etc/rc.d/init.d/shorewall restart
# You can use the following command to clear all shorewall rules
/sbin/shorewall clear
# Configure shorewall to auto start at boot time
/sbin/chkconfig shorewall on
# Use nmap from a different system to ensure that your firewall rules are in place
# Multiple IP address to single interface
# Reference:http://www.shorewall.net/Shorewall_and_Aliased_Interfaces.html#id2491727
# Ensure that all IP addresses ( non virtual ie. additional IP addresses on separate lan cards ) are configured in the /etc/shorewall/interfaces
# eg.
vi /etc/shorewall/interfaces
#ZONE INTERFACE BROADCAST OPTIONS
net eth1 210.210.23.26 norfc1918,routefilter,tcpflags,logmartians,nosmurfs
# The BROADCAST address can be ignored above and instead you can put a -
#RFC-1918 reserves several Private IP address ranges for use in private networks:
10.0.0.0 - 10.255.255.255
172.16.0.0 - 172.31.255.255
192.168.0.0 - 192.168.255.255
#If your IP address falls in any of the above range, then please remove "norfc1918" in the options section of the interfaces file
# If you have a non-static DHCP IP address,add "detect" in the "broadcast" section and add “dhcp” to the option list.
# If you are using virtual IP addresses (eg. eth0:0,eth0:1 etc,) configured for a single ethernet card, then you can ignore the above setting in /etc/shorewall/interfaces
# If you have muliple IP addresses and want a sshd to be available on a single IP address (eg. 210.210.23.26 )instead of all IP adresses on the server ,then do this
vi /etc/shorewall/rules
#ACCEPT net $FW tcp 22
ACCEPT net $FW:210.210.23.26 tcp 22
/sbin/shorewall clear
/etc/rc.d/init.d/shorewall restart
# Remove the firewall_reset cron job and the entries in /etc/shorewall/routestopped after shorewall is run and firewall behaves as expected.
http://www.shorewall.net/shorewall_setup_guide.htm
# Backup your existing Iptables configuration so that you can revert back in case something goes wrong
cp -a /etc/sysconfig/iptables /etc/sysconfig/iptables_backup_
# Deploying a safety net to ensure that you dont get locked out
Reference : http://www.iptablesrocks.org/guide/safetynet.php
vi /root/firewall_reset
############
# Iptables firewall reset script
*filter
:INPUT ACCEPT [164:15203]
:FORWARD ACCEPT [0:0]
:OUTPUT ACCEPT [147:63028]
COMMIT
*mangle
:PREROUTING ACCEPT [164:15203]
:INPUT ACCEPT [164:15203]
:FORWARD ACCEPT [0:0]
:OUTPUT ACCEPT [147:63028]
:POSTROUTING ACCEPT [147:63028]
COMMIT
*nat
:PREROUTING ACCEPT [14:672]
:POSTROUTING ACCEPT [9:684]
:OUTPUT ACCEPT [9:684]
COMMIT
###########
# Test if the above script works and throws no error
/sbin/iptables-restore < /root/firewall_reset
/sbin/iptables -L
# The output should be similar to the following
###
Chain FORWARD (policy ACCEPT)
target prot opt source destination
Chain INPUT (policy ACCEPT)
target prot opt source destination
Chain OUTPUT (policy ACCEPT)
target prot opt source destination
###
# restore your orginal firewall configuration and proceed
/sbin/iptables-restore < /etc/sysconfig/iptables_backup_
# Confirm that your original rules have been restored by running the following command
/sbin/iptables -L
# Create a crontab entry that resets the firewall every 15 minutes
crontab -e
0,15,30,45 * * * * /sbin/iptables-restore < /root/firewall_reset
# Please ensure that you comment out this line after you have succesfully tested you shorewall working.
# Reference:http://www.shorewall.net/shorewall_quickstart_guide.htm
# Before installing ,check if iproute and shorewall already exist
rpm -qa | grep -i "iproute"
rpm -qa | grep -i "shorewall"
# If iproute doesn't exist then proceed as follows
yum install iproute
# Shorewall Installation
# Using Yum
yum install shorewall
# Using RPM
# In most cases shorewall would not exist in yum repositories so proceed as follows for the rpm installation
References :
http://www.shorewall.net/Install.htm
http://www.shorewall.net/download.htm
Download the shorewall and shorewall-perl rpm package
cd /tmp
wget http://www.invoca.ch/pub/packages/shorewall/4.2/shorewall-4.2.5/shorewall-4.2.5-3.noarch.rpm
wget http://www.invoca.ch/pub/packages/shorewall/4.2/shorewall-4.2.5/shorewall-perl-4.2.5-3.noarch.rpm
rpm -ivh shorewall-perl-4.2.5-3.noarch.rpm shorewall-4.2.5-3.noarch.rpm
#Setting up Shorewall on a standalone Linux system with a single static IP address
Reference :http://www.shorewall.net/standalone.htm
# Add your IP address (IP address of the system/gateway you are connecting from and not the server IP address where you are installing shorewall) to the /etc/shorewall/routestopped file to ensure that you stay connected when the firewall restarts.You can find your IP address by visiting http://whatismyip.com
cp -a /etc/shorewall/routestopped /etc/shorewall/routestopped.orig
vi /etc/shorewall/routestopped
# eg. if your IP address ( the system/gateway you are connecting from) is 59.144.118.69
#INTERFACE HOST(S)
eth0 59.144.0.0/24
# You can also add a CIDR number to indicate a range of IPs from which connection will not break
# For eg. if you want to keep alive connections from 192.168.0.1 to 192.168.0.254 during the firewall restart add the following line
#INTERFACE HOST(S)
eth0 192.168.0.0/24
# Find the sample configuration files by running
rpm -ql shorewall | fgrep one-interface
cp -a /usr/share/doc/shorewall-4.2.5/Samples/one-interface /tmp/
cd /tmp/one-interface
# Confirm your ethernet interface ( to check if you have a single lan card)
/sbin/ifconfig -a
vi interfaces
########
#ZONE INTERFACE BROADCAST OPTIONS
net eth0 210.210.18.90 norfc1918,routefilter,tcpflags,logmartians,nosmurfs
########
# The BROADCAST address can be ignored above and instead you can put a -
#RFC-1918 reserves several Private IP address ranges for use in private networks:
10.0.0.0 - 10.255.255.255
172.16.0.0 - 172.31.255.255
192.168.0.0 - 192.168.255.255
#If your IP address falls in any of the above range, then please remove "norfc1918" in the options section of the interfaces file
# If you have a non-static DHCP IP address,add "detect" in the "broadcast" section and add “dhcp” to the option list.
# Configuration of rules
# You can find custom rules files by running
ls /usr/share/shorewall/macro.*
# You can then use these macros in your shorewall rules file
# For eg. if you want to allow access to your web server running TCP Port 80 and SSHD running on TCP port 22 do the following
# Tip: You can identify the network services running on your server bu issuing the following command.
/bin/netstat -luntp
# Based on the output you get , you can decide which services to allow remote access or not
cd /tmp/one-interface
vi rules
#######
#ACTION SOURCE DESTINATION PROTO DEST PORT(S)
Web/ACCEPT net $FW
SSH/ACCEPT net $FW
######
# You can also add the above rules in this way.
vi rules
#########
#ACTION SOURCE DESTINATION PROTO DEST PORT(S)
ACCEPT net $FW tcp 80
ACCEPT net $FW tcp 22
#########
# You can also add the following rule if you see port TCP 113 as closed in your nmap scan.
DROP net $FW tcp 113
If you want to allow conections to let's say the ssh port only from specific IP Addresses on the internet add the following
ACCEPT net:192.0.2.16/28,192.0.2.44 fw tcp 22
# Please ensure that you check the individual macros you applies from /usr/share/shorewall/macro.* to ensure that they work as desired
# You must enable startup by editing /etc/shorewall/shorewall.conf and setting STARTUP_ENABLED=Yes
cp -a /tmp/one-interface/shorewall.conf /tmp/one-interface/shorewall.conf.orig
vi /tmp/one-interface/shorewall.conf
# Modify the lines as shown
#STARTUP_ENABLED=No
STARTUP_ENABLED=Yes
#IPTABLES=
IPTABLES=/sbin/iptables
#IP_FORWARDING=On
IP_FORWARDING=Off
#DISABLE_IPV6=Yes
# Copy your configuration files to appropriate locations
cd /etc/shorewall/
cp -a policy policy.orig
cp -a rules rules.orig
cp -a interfaces interfaces.orig
cp -a zones zones.orig
cp -a /tmp/one-interface/* /etc/shorewall/
rm -rf /tmp/one-interface/
/etc/rc.d/init.d/shorewall restart
# You can use the following command to clear all shorewall rules
/sbin/shorewall clear
# Configure shorewall to auto start at boot time
/sbin/chkconfig shorewall on
# Use nmap from a different system to ensure that your firewall rules are in place
# Multiple IP address to single interface
# Reference:http://www.shorewall.net/Shorewall_and_Aliased_Interfaces.html#id2491727
# Ensure that all IP addresses ( non virtual ie. additional IP addresses on separate lan cards ) are configured in the /etc/shorewall/interfaces
# eg.
vi /etc/shorewall/interfaces
#ZONE INTERFACE BROADCAST OPTIONS
net eth1 210.210.23.26 norfc1918,routefilter,tcpflags,logmartians,nosmurfs
# The BROADCAST address can be ignored above and instead you can put a -
#RFC-1918 reserves several Private IP address ranges for use in private networks:
10.0.0.0 - 10.255.255.255
172.16.0.0 - 172.31.255.255
192.168.0.0 - 192.168.255.255
#If your IP address falls in any of the above range, then please remove "norfc1918" in the options section of the interfaces file
# If you have a non-static DHCP IP address,add "detect" in the "broadcast" section and add “dhcp” to the option list.
# If you are using virtual IP addresses (eg. eth0:0,eth0:1 etc,) configured for a single ethernet card, then you can ignore the above setting in /etc/shorewall/interfaces
# If you have muliple IP addresses and want a sshd to be available on a single IP address (eg. 210.210.23.26 )instead of all IP adresses on the server ,then do this
vi /etc/shorewall/rules
#ACCEPT net $FW tcp 22
ACCEPT net $FW:210.210.23.26 tcp 22
/sbin/shorewall clear
/etc/rc.d/init.d/shorewall restart
# Remove the firewall_reset cron job and the entries in /etc/shorewall/routestopped after shorewall is run and firewall behaves as expected.
How to Secure a Linux Box
#Reference:http://www.cisecurity.org/bench_linux.html
#Note:This tutorial is based on Fedora Core 4.Should be valid for a newer version of Fedora too.The reader is advised to read the CIS Benchmark pdf after completing all activities mentioned in this document.
# Setup an informative command prompt
export PS1="-\$?-(\u@\h) \w > "
# Hostname Setup
Reference:http://www.cpqlinux.com/hostname.html
# Please ensure that the correct hostname is setup in the following files.The hostname should ideally match the PTR record of the system IP
/etc/hosts
/etc/sysconfig/network
# Use echo to set the hostname in the file below eg.
echo yourhostname > /proc/sys/kernel/hostname
/proc/sys/kernel/hostname
# Virtual IP Setup
cd /etc/sysconfig/network-scripts
#Check for existing network adapters with the command:
ls ifcfg-*
#In most instances, you will see the files ifcfg-eth0 and ifcfg-lo. If you see other files with any other names and are unfamiliar with configuring TCP/IP, you may want to consult with your system administrator before proceeding.
cp -a ifcfg-eth0 ifcfg-eth0:0
cp -a ifcfg-eth0 ifcfg-eth0:1
# Ensure the following lines are configured as
vi icfg-eth0:0
DEVICE=eth0:0
IPADDR=
VLAN=yes
vi icfg-eth0:1
DEVICE=eth0:1
IPADDR=
VLAN=yes
#Disable IPV6
cp -a /etc/modprobe.conf /etc/modprobe_backup.conf
echo "alias net-pf-10 off" >> /etc/modprobe.conf
echo "alias ipv6 off" >> /etc/modprobe.conf
/etc/init.d/ip6tables stop
/sbin/chkconfig --level 35 ip6tables off
# Restart the network to effect changes
/sbin/service network restart
# Edit /etc/hosts and add a line for your new addresses and name such as:
127.0.0.1 localhost.localdomain localhost
x.x.x.x newhost1.yourdomain.com
x.x.x.x newhost2.yourdomain.com
# Disabling selinux
vi /etc/sysconfig/selinux
#check for the line SELINUX
SELINUX=disabled
# Date and Time Configuration
Ref:http://www.linuxsa.org.au/tips/time.html
ln -sf /usr/share/zoneinfo/Asia/Calcutta /etc/localtime
date monthdayhourminyear
yum install ntp
#Configure a cron job to update time every night at 12 AM
00 00 * * * /usr/sbin/ntpdate 0.pool.ntp.org 1.pool.ntp.org
# Configure Automatic Updates using yum.Fedora Core 6 or above will have yum-updatesd instead of yum
/sbin/chkconfig yum on
/sbin/service yum start
# If you wish to disable autoupdation of some package, eg.firefox and cacti ,do the following
cp -a /etc/yum.conf /etc/yum.conf.orig
vi /etc/yum.conf
# Add the following line
exclude=firefox cacti
# For Fedora Core 6 or above do this
# Reference: http://www.die.net/doc/linux/man/man5/yum-updatesd.conf.5.html
cp -a /etc/updatedb.conf /etc/updatedb.conf.orig
vi /etc/yum/yum-updatesd.conf
#########
# Configure the entries as shown below
# automatically install updates
do_update = yes
# automatically download updates
do_download = yes
# automatically download deps of updates
do_download_deps = yes
#########
/sbin/chkconfig yum-updatesd on
/sbin/service yum-updatesd start
crontab -e
00 0 * * * yum -y update
# Configuring updatedb
cp -a /etc/updatedb.conf /etc/updatedb.conf.orig
vi /etc/updatedb.conf
#Configure the following values to yes
#DAILY_UPDATE=no
DAILY_UPDATE=yes
# Configuring Log Compression
cp -a /etc/logrotate.conf /etc/logrotate.conf.orig
vi /etc/logrotate.conf
# uncomment this if you want your log files compressed
compress
# Unalias cp and mv
unalias mv cp
# Firewall ,Reactive IDS and SSH bruteforce prevention setup
Please install and configure shorewall ,psad and fail2ban by referring their separate howtos
# Apache Installation
# Check if Apache is already installed
rpm -qa httpd
service httpd status
# If httpd is not installed proceed with the apache installation as follows
yum install httpd
yum install httpd-devel
# Apache Hardening
Edit httpd.conf file as follows.
cd /etc/httpd/conf/
cp -a httpd.conf httpd.conf.orig
vi /etc/httpd/conf/httpd.conf
# Edit the following entry as follows
#ServerTokens OS
ServerTokens Prod
#ServerSignature On
ServerSignature Off
#Ref:http://www.slac.stanford.edu/comp/unix/apache-security.html
#http://publib.boulder.ibm.com/httpserv/ihsdiag/http_trace.html
# Disabling Indexing
# Ref: http://www.ducea.com/2006/06/26/apache-tips-tricks-disable-directory-indexes/
# In Main Server Configurations
Options -Indexes
# To disable Trace and Track Methods:
For apache version 1.3.34 (or later 1.3.x versions), or apache 2.0.55 (or later), in section 1, add the line
TraceEnable off
For older versions of apache, see below.
#Add Before Secton 3 and in each virtual host configuration section/file
# Block access: SLAC addition
RewriteEngine On
RewriteCond %{REQUEST_METHOD} ^(TRACE|TRACK)
RewriteRule .* - [F]
# End block access rule
# Disabling welcome page
cp -a /etc/httpd/conf.d/welcome.conf /etc/httpd/conf.d/welcome.conf.orig
vi /etc/httpd/conf.d/welcome.conf
# Comment all the lines in the file
# Disabling configuration by .htaccess
AllowOverride None
# Restart Apache
/etc/rc.d/init.d/httpd start
# MySQL Installation
# Check if MySQL is already installed
rpm -qa mysql
service mysqld status
# If Mysqld Daemon is not installed proceed with the MySQL installation as follows
yum install mysql-server
yum install mysql
yum install mysql-devel
#Start MySQL for the first time
mysql_install_db
/etc/rc.d/init.d/mysqld start
#Note:In case you have issues starting Mysql server for the first time and you see error messggaes saying that tmp files could not be created,please run bastille configuration again and answer N to "Q: Would you like to install TMPDIR/TMP scripts?" question reboot the system.Post reboot you can start Mysqld
/sbin/chkconfig mysqld on
#Mysql Hardening:
mysql
# Removing anonymous login:
DELETE FROM mysql.user WHERE User = '';
FLUSH PRIVILEGES;
quit
#Setting Mysql Root password:
/usr/bin/mysqladmin -u root password 'yourpassword'
/usr/bin/mysqladmin -u root -h password 'yourpassword'
# Delete test database
mysql
drop database test;
# Configure Mysql to not listen for external connections
cp -a /etc/my.cnf /etc/my.cnf.orig
vi /etc/my.cnf
[mysqld]
skip-networking
#Perl Installation
#check if perl is installed or not
rpm -qa perl
# If Perl is not installed proceed with the Perl installation as follows
yum install perl
# Cpan configuration
# Before running cpan ensure that gcc is installed else some modules will throw errors during compilation
rpm -qa gcc
# Install gcc if not found
yum install gcc
# Run and configure cpan
cpan
# A first time set of configuration questions will be asked
# Update cpan by running
cpan
install Bundle::CPAN
reload cpan
# Bastille Hardening
#Bastille Installation
cd /tmp
wget http://nchc.dl.sourceforge.net/sourceforge/bastille-linux/Bastille-3.2.1-0.1.noarch.rpm
# Ref: http://www.bastille-linux.org/running_bastille_on.htm#top
rpm -ivh Bastille-3.2.1-0.1.noarch.rpm
# Install Curses from cpan
# Please check wheather ncurses-devel is installed
rpm -qa ncurses-devel
# If ncurses is not installed install it as follows
yum install ncurses-devel
# Install Curses module as follows
cpan
install Curses
# Run bastille text mode hardening as follows
/usr/sbin/bastille -c
# Respond to all questions
# Check your score
/usr/sbin/bastille --report
# ICMP Hardening
# Check and Download sysctl RPM
yum install sysctl
# Enter the following in /etc/sysctl.conf file
net.ipv4.icmp_echo_ignore_all = 1
net.ipv4.icmp_echo_ignore_broadcasts = 1
net.ipv4.icmp_ignore_bogus_error_responses = 1
net.ipv4.conf.all.accept_source_route = 0
net.ipv4.conf.all.accept_redirects = 0
net.ipv4.tcp_max_syn_backlog = 4096
net.ipv4.tcp_syncookies=1
net.ipv4.conf.all.rp_filter = 1
net.ipv4.conf.all.secure_redirects = 0
net.ipv4.conf.default.rp_filter = 1
net.ipv4.conf.default.accept_source_route = 0
net.ipv4.conf.default.accept_redirects = 0
net.ipv4.conf.default.secure_redirects = 0
net.ipv4.tcp_max_orphans = 256
net.ipv4.conf.all.log_martians = 1
# Diable Forwarding and Gateway functionality
net.ipv4.ip_forward = 0
net.ipv4.conf.all.send_redirects = 0
net.ipv4.conf.default.send_redirects = 0
#Check for the syntax in the file /etc/sysctl.conf
/sbin/sysctl -p
OR
/sbin/iptables -A INPUT -j REJECT -p icmp --icmp-type 13
/sbin/iptables -A OUTPUT -j REJECT -p icmp --icmp-type 14
# Detailed audit trail setup
Ref: http://www.cyberciti.biz/tips/howto-log-user-activity-using-process-accounting.html
yum install psacct
chkconfig psacct on
/etc/init.d/psacct start
# Rootkit Hunter
Reference:http://www.rootkit.nl/
Installation:
# Download rkhunter from http://www.rootkit.nl/projects/rootkit_hunter.html
cd /tmp
wget http://nchc.dl.sourceforge.net/sourceforge/rkhunter/rkhunter-1.3.2.tar.gz
tar zxvf rkhunter-1.3.2.tar.gz
cd rkhunter-1.3.2
sh installer.sh --layout default --install
# Running Rkhunter
/usr/local/bin/rkhunter --update
/usr/local/bin/rkhunter -c --createlogfile --quiet
The report will be generated at /var/log/rkhunter.log
#Configure rkhunter for automatic update
crontab -e
00 0 * * * /usr/local/bin/rkhunter --update -q
# SSHD Hardening
cp -a /etc/ssh/sshd_config /etc/ssh/sshd_config.orig
vi /etc/ssh/sshd_config
#change port no from 22 to 222
Port 222
PermitRootLogin no
Banner /etc/issue
#This banner is generated when you ran Bastille previously.
#Prevent X11 forwarding
X11Forwarding no
#Don't read the user's ~/.rhosts and ~/.shosts files uncomment IgnoreRhosts yes
IgnoreRhosts yes
# The following switch is not found in Fedora 4.Please check the switch to ensure that it exists #before making this entry
RhostsAuthentication no
RhostsRSAAuthentication no
HostbasedAuthentication no
PermitEmptyPasswords no
#Note:Before restarting ssh please create a non-root account.
Restart sshd
/etc/rc.d/init.d/sshd restart
# Nessus Setup
# Read the Nessus How to file for installing and running Nessus
# CIS benchmark security exercise
# Download the CIS benchmark locally from http://www.cisecurity.org/bench_linux.html and copy the do-backup.sh file in /root and run the same to backup all important directories and files
cd /root
chmod 755 do-backup.sh
./do-backup.sh
# Uninstalling xinetd
rpm -qa xinetd
rpm -e xinetd-versionnumber
# Incase you still want to use some services in xinetd ,please run the following comands to stop these unnnecessary services.
cd /etc/xinetd.d
for FILE in chargen chargen-udp cups-lpd cups daytime \ daytime-udp echo echo-udp eklogin ekrb5-telnet finger \ gssftp imap imaps ipop2 ipop3 krb5-telnet klogin kshell \ ktalk ntalk pop3s rexec rlogin rsh rsync servers services \ sgi_fam talk telnet tftp time time-udp vsftpd wu-ftpd do
chkconfig ${FILE} off done
# Disable GUI
sed -e 's/id:5:initdefault:/id:3:initdefault:/' \
< /etc/inittab-preCIS > /etc/inittab
chown root:root /etc/inittab
chmod 0600 /etc/inittab
diff /etc/inittab-preCIS /etc/inittab
# Disable Unneccessary services
# Please review all services listed in the following script before running.
vi disable_unwanted_services
########
for FILE in apmd avahi-daemon canna cups-config-daemon FreeWnn gpm hidd hpoj hplip innd irda isdn kdcrotate lvs mars-nwe messagebus oki4daemon privoxy rstatd rusersd rwalld rwhod wine; do
/sbin/service $FILE stop
/sbin/chkconfig $FILE off
done
for FILE in nfs nfslock autofs ypbind ypserv yppasswdd portmap smb netfs lpd tux snmpd named postgresql webmin kudzu squid cups ip6tables pcmcia bluetooth mDNSResponder; do
/sbin/service $FILE stop
/sbin/chkconfig $FILE off
done
########
chmod 755 disable_unwanted_services
./disable_unwanted_services
# Assign Proper permissions to log files
chmod o-rwx boot.log* cron* dmesg ksyms* httpd/* maillog* messages* news/* pgsql rpmpkgs* samba/* sa/* scrollkeeper.log secure* spooler* squid/* vbox/* wtmp
chmod o-rx boot.log* cron* maillog* messages* pgsql secure* spooler* squid/* sa/*
chmod g-w boot.log* cron* dmesg httpd/* ksyms* maillog* messages* pgsql rpmpkgs* samba/* sa/* scrollkeeper.log secure* spooler*
chmod g-rx boot.log* cron* maillog* messages* pgsql secure* spooler*
chmod o-w gdm/ httpd/ news/ samba/ squid/ sa/ vbox/
chmod o-rx httpd/ samba/ squid/ sa/
chmod g-w gdm/ httpd/ news/ samba/ squid/ sa/ vbox/
chmod g-rx httpd/ samba/ sa/
chmod u-x kernel syslog loginlog
# Verify passwd, shadow, and group File Permissions
cd /etc
chown root:root passwd shadow group
chmod 644 passwd group
chmod 400 shadow
# Allowing only root access to Cron and At
cd /etc/
rm -f cron.deny at.deny
echo root > cron.allow
echo root > at.allow
chown root:root cron.allow at.allow
chmod 400 cron.allow at.allow
# Restrict Permissions On crontab Files
chown root:root /etc/crontab
chmod 400 /etc/crontab
chown -R root:root /var/spool/cron
chmod -R go-rwx /var/spool/cron
cd /etc
ls | grep cron | grep -v preCIS | xargs chown -R root:root
ls | grep cron | grep -v preCIS | xargs chmod -R go-rwx
# Block all system accounts from loging on to the server
cd /root
vi lock_system_accounts
####
cd /etc
for NAME in `cut -d: -f1 /etc/passwd`; do
MyUID=`id -u $NAME`
if [ $MyUID -lt 500 -a $NAME != 'root' ]; then
/usr/sbin/usermod -L -s /dev/null $NAME
fi
done
###
chmod 755 lock_system_accounts
./lock_system_accounts
rm -rf lock_system_accounts
# Check for empty password accounts
awk -F: '($2 == "") { print $1 }' /etc/shadow
# Set Account Expiration Parameters On Active Accounts
cd /etc
awk '($1 ~ /^PASS_MAX_DAYS/) { $2="90" }
($1 ~ /^PASS_MIN_DAYS/) { $2="7" }
($1 ~ /^PASS_WARN_AGE/) { $2="28" }
($1 ~ /^PASS_MIN_LEN/) { $2="6" }
{ print } ' login.defs-preCIS > login.defs
diff login.defs-preCIS login.defs
chown root:root login.defs
chmod 640 login.defs
diff login.defs-preCIS login.defs
useradd -D -f 7
diff /etc/default/useradd-preCIS /etc/default/useradd
for NAME in `cut -d: -f1 /etc/passwd`; do
uid=`id -u $NAME`
if [ $uid -ge 500 -a $uid != 65534 ]; then
chage -m 7 -M 90 -W 28 -I 7 $NAME
fi
done
diff shadow-preCIS shadow
# Verify No Legacy '+' Entries Exist In passwd, shadow, And group Files
grep ^+: /etc/passwd /etc/shadow /etc/group
# No '.' or Group/World-Writable Directory In Root's $PATH
#To find ‘.’ in $PATH:
echo $PATH | egrep '(^|:)(\.|:|$)'
#To find group- or world-writable directories in $PATH:
find `echo $PATH | tr ':' ' '` -type d \( -perm -002 -o -perm -020 \) -ls
#These commands should produce no output.
#User Home Directories Should Be Mode 750 or More Restrictive
vi user_directories_permission
###############
for DIR in `awk -F: '($3 >= 500) { print $6 }' /etc/passwd`; do
chmod g-w $DIR
chmod o-rwx $DIR
done
##############
chmod 755 user_directories_permission
./user_directories_permission
#No User Dot-Files Should Be World-Writable
vi user_dot_files_non_worldwritable
#############
for DIR in `awk -F: '($3 >= 500) { print $6 }' /etc/passwd`; do
for FILE in $DIR/.[A-Za-z0-9]*; do
if [ ! -h "$FILE" -a -f "$FILE" ]; then
chmod go-w "$FILE"
fi
done
done
#########
chmod 755 user_dot_files_non_worldwritable
./user_dot_files_non_worlwritable
#Remove User .netrc Files
find / -name .netrc
# If any .netrc file is found then run the following script to remove
vi remove_netrc
###############
for DIR in `cut -f6 -d: /etc/passwd`; do
if [ -e $DIR/.netrc ]; then
echo "Removing $DIR/.netrc"
rm -f $DIR/.netrc fi
done
###############
chmod 755 remove_netrc
./remove_netrc
#Set Default umask For Users
vi set_default_umask
#########
cd /etc
for FILE in profile csh.login csh.cshrc bashrc; do
if ! egrep -q 'umask.*77' $FILE ; then
echo "umask 077" >> $FILE
fi
chown root:root $FILE
chmod 444 $FILE
diff ${FILE}-preCIS $FILE
done
cd /root
for FILE in .bash_profile .bashrc .cshrc .tcshrc; do
if ! egrep -q 'umask.*77' $FILE ; then
echo "umask 077" >> $FILE # See description
fi
chown root:root $FILE
diff ${FILE}-preCIS $FILE
done
###########
chmod 755 set_default_umask
./set_default_umask
# Disable Core Dumps
cp -a /etc/security/limits.conf /etc/security/limits.conf.orig
vi /etc/security/limits.conf
#Add the following two lines.In future you can enable core dumps for invidual users if required.
* soft core 0
* hard core 0
####
# Limit Access To The Root Account From su
# Warning:Please add your account to the wheel group before proceeding with this activity else you # will not be able to su.
# eg. /usr/sbin/usermod -G wheel
# In case you want to create a new account and add it to the wheel group, then run this command
/usr/sbin/useradd -G wheel
# Limit Access To The Root Account From su
cd /etc/pam.d/
cp -a su su_backup_18_dec_2006
vi su
##Uncommenting this line allows only the users in the wheel group to become root by using the su command and entering the root password.All other users get the message Incorrect Password
auth required /lib/security/$ISA/pam_wheel.so use_uid
# Banners
# Note:/etc/issue banner should have already been created by BastilleIf you havent run Bastille please create an appropriate banner file /etc/issue as follows
***************************************************************************
NOTICE TO USERS
This computer system is the private property of, whether
individual, corporate or government. It is for authorized use only.
Users (authorized or unauthorized) have no explicit or implicit
expectation of privacy.
Any or all uses of this system and all files on this system may be
intercepted, monitored, recorded, copied, audited, inspected, and
disclosed to your employer, to authorized site, government, and law
enforcement personnel, as well as authorized officials of government
agencies, both domestic and foreign.
By using this system, the user consents to such interception, monitoring,
recording, copying, auditing, inspection, and disclosure at the
discretion of such personnel or officials. Unauthorized or improper use
of this system may result in civil and criminal penalties and
administrative or disciplinary action, as appropriate. By continuing to use
this system you indicate your awareness of and consent to these terms
and conditions of use. LOG OFF IMMEDIATELY if you do not agree to the
conditions stated in this warning.
****************************************************************************
cp -a issue.net issue_backup_todays_date.net
cp -a issue issue.net
# Contents of /etc/motd are displayed after a user logins in so its not neccessary to create a #banner in that file
chown root:root /etc/motd /etc/issue /etc/issue.net
chmod 644 /etc/motd /etc/issue /etc/issue.net
# Removing unnecessary applications
# Please refer http://www.mjmwired.net/resources/mjm-services-fc6.html for the list of services and their uses and recommendations on which to disable
cd /etc/init.d
ls
# Verify the softwares that are listed here.Remove all unnecesaasy packages as show below.
# For eg. if you see bluetooth and you want to identify what package it represnts, do the following
rpm -qf bluetooth
bluez-utils-2.15-7
yum remove bluez-utils-2.15-7
# Do this for all other softwares like portmap,apmd,cups,isdn,irda,etc.
# RHEL comes with virtualisation enabled.Due to this you may see an additional network adapter ( virbr0 ) when you run /sbin/ifconfig -a
# This can be removed by following these steps
#Source :http://www.cyberciti.biz/faq/rhel-fedora-centos-linux-remove-network-interface-virbr0/
yum groupremove "Virtualization"
# Type y when it lists the following pakcages to be removed
libvirt
libvirt-python
rhn-virtualization-host
This will also remove the virbr0 network adapter
#Firewall Configuration
/bin/netstat -ltunp
# The above command will show you list of processes running on specific ports.Please ensure that unnecassary services are disabled and uninstalled as shown in the above point.
# Open required ports in iptables using Shorewall (Please refer the separate Howto)
/usr/sbin/lokkit
# Remove All Compilers and Assemblers
#The following command will help you identify the packages installed on your system
rpm -qa | egrep "^gcc|java|bin86|dev86|nasm"
#Identify the package and remove the ones you dont need
#Verify That No Unauthorized UID 0 Accounts Exists
getent passwd | awk -F: '$3 == "0" { print $1 }'
#should return only the word "root", unless additional uid 0 accounts have been specifically authorized. Having #multiple uid 0 accounts are acceptable if the accounts are authorized, but not recommended for some situations.
#Note:This tutorial is based on Fedora Core 4.Should be valid for a newer version of Fedora too.The reader is advised to read the CIS Benchmark pdf after completing all activities mentioned in this document.
# Setup an informative command prompt
export PS1="-\$?-(\u@\h) \w > "
# Hostname Setup
Reference:http://www.cpqlinux.com/hostname.html
# Please ensure that the correct hostname is setup in the following files.The hostname should ideally match the PTR record of the system IP
/etc/hosts
/etc/sysconfig/network
# Use echo to set the hostname in the file below eg.
echo yourhostname > /proc/sys/kernel/hostname
/proc/sys/kernel/hostname
# Virtual IP Setup
cd /etc/sysconfig/network-scripts
#Check for existing network adapters with the command:
ls ifcfg-*
#In most instances, you will see the files ifcfg-eth0 and ifcfg-lo. If you see other files with any other names and are unfamiliar with configuring TCP/IP, you may want to consult with your system administrator before proceeding.
cp -a ifcfg-eth0 ifcfg-eth0:0
cp -a ifcfg-eth0 ifcfg-eth0:1
# Ensure the following lines are configured as
vi icfg-eth0:0
DEVICE=eth0:0
IPADDR=
VLAN=yes
vi icfg-eth0:1
DEVICE=eth0:1
IPADDR=
VLAN=yes
#Disable IPV6
cp -a /etc/modprobe.conf /etc/modprobe_backup.conf
echo "alias net-pf-10 off" >> /etc/modprobe.conf
echo "alias ipv6 off" >> /etc/modprobe.conf
/etc/init.d/ip6tables stop
/sbin/chkconfig --level 35 ip6tables off
# Restart the network to effect changes
/sbin/service network restart
# Edit /etc/hosts and add a line for your new addresses and name such as:
127.0.0.1 localhost.localdomain localhost
x.x.x.x newhost1.yourdomain.com
x.x.x.x newhost2.yourdomain.com
# Disabling selinux
vi /etc/sysconfig/selinux
#check for the line SELINUX
SELINUX=disabled
# Date and Time Configuration
Ref:http://www.linuxsa.org.au/tips/time.html
ln -sf /usr/share/zoneinfo/Asia/Calcutta /etc/localtime
date monthdayhourminyear
yum install ntp
#Configure a cron job to update time every night at 12 AM
00 00 * * * /usr/sbin/ntpdate 0.pool.ntp.org 1.pool.ntp.org
# Configure Automatic Updates using yum.Fedora Core 6 or above will have yum-updatesd instead of yum
/sbin/chkconfig yum on
/sbin/service yum start
# If you wish to disable autoupdation of some package, eg.firefox and cacti ,do the following
cp -a /etc/yum.conf /etc/yum.conf.orig
vi /etc/yum.conf
# Add the following line
exclude=firefox cacti
# For Fedora Core 6 or above do this
# Reference: http://www.die.net/doc/linux/man/man5/yum-updatesd.conf.5.html
cp -a /etc/updatedb.conf /etc/updatedb.conf.orig
vi /etc/yum/yum-updatesd.conf
#########
# Configure the entries as shown below
# automatically install updates
do_update = yes
# automatically download updates
do_download = yes
# automatically download deps of updates
do_download_deps = yes
#########
/sbin/chkconfig yum-updatesd on
/sbin/service yum-updatesd start
crontab -e
00 0 * * * yum -y update
# Configuring updatedb
cp -a /etc/updatedb.conf /etc/updatedb.conf.orig
vi /etc/updatedb.conf
#Configure the following values to yes
#DAILY_UPDATE=no
DAILY_UPDATE=yes
# Configuring Log Compression
cp -a /etc/logrotate.conf /etc/logrotate.conf.orig
vi /etc/logrotate.conf
# uncomment this if you want your log files compressed
compress
# Unalias cp and mv
unalias mv cp
# Firewall ,Reactive IDS and SSH bruteforce prevention setup
Please install and configure shorewall ,psad and fail2ban by referring their separate howtos
# Apache Installation
# Check if Apache is already installed
rpm -qa httpd
service httpd status
# If httpd is not installed proceed with the apache installation as follows
yum install httpd
yum install httpd-devel
# Apache Hardening
Edit httpd.conf file as follows.
cd /etc/httpd/conf/
cp -a httpd.conf httpd.conf.orig
vi /etc/httpd/conf/httpd.conf
# Edit the following entry as follows
#ServerTokens OS
ServerTokens Prod
#ServerSignature On
ServerSignature Off
#Ref:http://www.slac.stanford.edu/comp/unix/apache-security.html
#http://publib.boulder.ibm.com/httpserv/ihsdiag/http_trace.html
# Disabling Indexing
# Ref: http://www.ducea.com/2006/06/26/apache-tips-tricks-disable-directory-indexes/
# In Main Server Configurations
Options -Indexes
# To disable Trace and Track Methods:
For apache version 1.3.34 (or later 1.3.x versions), or apache 2.0.55 (or later), in section 1, add the line
TraceEnable off
For older versions of apache, see below.
#Add Before Secton 3 and in each virtual host configuration section/file
# Block access: SLAC addition
RewriteEngine On
RewriteCond %{REQUEST_METHOD} ^(TRACE|TRACK)
RewriteRule .* - [F]
# End block access rule
# Disabling welcome page
cp -a /etc/httpd/conf.d/welcome.conf /etc/httpd/conf.d/welcome.conf.orig
vi /etc/httpd/conf.d/welcome.conf
# Comment all the lines in the file
# Disabling configuration by .htaccess
AllowOverride None
# Restart Apache
/etc/rc.d/init.d/httpd start
# MySQL Installation
# Check if MySQL is already installed
rpm -qa mysql
service mysqld status
# If Mysqld Daemon is not installed proceed with the MySQL installation as follows
yum install mysql-server
yum install mysql
yum install mysql-devel
#Start MySQL for the first time
mysql_install_db
/etc/rc.d/init.d/mysqld start
#Note:In case you have issues starting Mysql server for the first time and you see error messggaes saying that tmp files could not be created,please run bastille configuration again and answer N to "Q: Would you like to install TMPDIR/TMP scripts?" question reboot the system.Post reboot you can start Mysqld
/sbin/chkconfig mysqld on
#Mysql Hardening:
mysql
# Removing anonymous login:
DELETE FROM mysql.user WHERE User = '';
FLUSH PRIVILEGES;
quit
#Setting Mysql Root password:
/usr/bin/mysqladmin -u root password 'yourpassword'
/usr/bin/mysqladmin -u root -h
# Delete test database
mysql
drop database test;
# Configure Mysql to not listen for external connections
cp -a /etc/my.cnf /etc/my.cnf.orig
vi /etc/my.cnf
[mysqld]
skip-networking
#Perl Installation
#check if perl is installed or not
rpm -qa perl
# If Perl is not installed proceed with the Perl installation as follows
yum install perl
# Cpan configuration
# Before running cpan ensure that gcc is installed else some modules will throw errors during compilation
rpm -qa gcc
# Install gcc if not found
yum install gcc
# Run and configure cpan
cpan
# A first time set of configuration questions will be asked
# Update cpan by running
cpan
install Bundle::CPAN
reload cpan
# Bastille Hardening
#Bastille Installation
cd /tmp
wget http://nchc.dl.sourceforge.net/sourceforge/bastille-linux/Bastille-3.2.1-0.1.noarch.rpm
# Ref: http://www.bastille-linux.org/running_bastille_on.htm#top
rpm -ivh Bastille-3.2.1-0.1.noarch.rpm
# Install Curses from cpan
# Please check wheather ncurses-devel is installed
rpm -qa ncurses-devel
# If ncurses is not installed install it as follows
yum install ncurses-devel
# Install Curses module as follows
cpan
install Curses
# Run bastille text mode hardening as follows
/usr/sbin/bastille -c
# Respond to all questions
# Check your score
/usr/sbin/bastille --report
# ICMP Hardening
# Check and Download sysctl RPM
yum install sysctl
# Enter the following in /etc/sysctl.conf file
net.ipv4.icmp_echo_ignore_all = 1
net.ipv4.icmp_echo_ignore_broadcasts = 1
net.ipv4.icmp_ignore_bogus_error_responses = 1
net.ipv4.conf.all.accept_source_route = 0
net.ipv4.conf.all.accept_redirects = 0
net.ipv4.tcp_max_syn_backlog = 4096
net.ipv4.tcp_syncookies=1
net.ipv4.conf.all.rp_filter = 1
net.ipv4.conf.all.secure_redirects = 0
net.ipv4.conf.default.rp_filter = 1
net.ipv4.conf.default.accept_source_route = 0
net.ipv4.conf.default.accept_redirects = 0
net.ipv4.conf.default.secure_redirects = 0
net.ipv4.tcp_max_orphans = 256
net.ipv4.conf.all.log_martians = 1
# Diable Forwarding and Gateway functionality
net.ipv4.ip_forward = 0
net.ipv4.conf.all.send_redirects = 0
net.ipv4.conf.default.send_redirects = 0
#Check for the syntax in the file /etc/sysctl.conf
/sbin/sysctl -p
OR
/sbin/iptables -A INPUT -j REJECT -p icmp --icmp-type 13
/sbin/iptables -A OUTPUT -j REJECT -p icmp --icmp-type 14
# Detailed audit trail setup
Ref: http://www.cyberciti.biz/tips/howto-log-user-activity-using-process-accounting.html
yum install psacct
chkconfig psacct on
/etc/init.d/psacct start
# Rootkit Hunter
Reference:http://www.rootkit.nl/
Installation:
# Download rkhunter from http://www.rootkit.nl/projects/rootkit_hunter.html
cd /tmp
wget http://nchc.dl.sourceforge.net/sourceforge/rkhunter/rkhunter-1.3.2.tar.gz
tar zxvf rkhunter-1.3.2.tar.gz
cd rkhunter-1.3.2
sh installer.sh --layout default --install
# Running Rkhunter
/usr/local/bin/rkhunter --update
/usr/local/bin/rkhunter -c --createlogfile --quiet
The report will be generated at /var/log/rkhunter.log
#Configure rkhunter for automatic update
crontab -e
00 0 * * * /usr/local/bin/rkhunter --update -q
# SSHD Hardening
cp -a /etc/ssh/sshd_config /etc/ssh/sshd_config.orig
vi /etc/ssh/sshd_config
#change port no from 22 to 222
Port 222
PermitRootLogin no
Banner /etc/issue
#This banner is generated when you ran Bastille previously.
#Prevent X11 forwarding
X11Forwarding no
#Don't read the user's ~/.rhosts and ~/.shosts files uncomment IgnoreRhosts yes
IgnoreRhosts yes
# The following switch is not found in Fedora 4.Please check the switch to ensure that it exists #before making this entry
RhostsAuthentication no
RhostsRSAAuthentication no
HostbasedAuthentication no
PermitEmptyPasswords no
#Note:Before restarting ssh please create a non-root account.
Restart sshd
/etc/rc.d/init.d/sshd restart
# Nessus Setup
# Read the Nessus How to file for installing and running Nessus
# CIS benchmark security exercise
# Download the CIS benchmark locally from http://www.cisecurity.org/bench_linux.html and copy the do-backup.sh file in /root and run the same to backup all important directories and files
cd /root
chmod 755 do-backup.sh
./do-backup.sh
# Uninstalling xinetd
rpm -qa xinetd
rpm -e xinetd-versionnumber
# Incase you still want to use some services in xinetd ,please run the following comands to stop these unnnecessary services.
cd /etc/xinetd.d
for FILE in chargen chargen-udp cups-lpd cups daytime \ daytime-udp echo echo-udp eklogin ekrb5-telnet finger \ gssftp imap imaps ipop2 ipop3 krb5-telnet klogin kshell \ ktalk ntalk pop3s rexec rlogin rsh rsync servers services \ sgi_fam talk telnet tftp time time-udp vsftpd wu-ftpd do
chkconfig ${FILE} off done
# Disable GUI
sed -e 's/id:5:initdefault:/id:3:initdefault:/' \
< /etc/inittab-preCIS > /etc/inittab
chown root:root /etc/inittab
chmod 0600 /etc/inittab
diff /etc/inittab-preCIS /etc/inittab
# Disable Unneccessary services
# Please review all services listed in the following script before running.
vi disable_unwanted_services
########
for FILE in apmd avahi-daemon canna cups-config-daemon FreeWnn gpm hidd hpoj hplip innd irda isdn kdcrotate lvs mars-nwe messagebus oki4daemon privoxy rstatd rusersd rwalld rwhod wine; do
/sbin/service $FILE stop
/sbin/chkconfig $FILE off
done
for FILE in nfs nfslock autofs ypbind ypserv yppasswdd portmap smb netfs lpd tux snmpd named postgresql webmin kudzu squid cups ip6tables pcmcia bluetooth mDNSResponder; do
/sbin/service $FILE stop
/sbin/chkconfig $FILE off
done
########
chmod 755 disable_unwanted_services
./disable_unwanted_services
# Assign Proper permissions to log files
chmod o-rwx boot.log* cron* dmesg ksyms* httpd/* maillog* messages* news/* pgsql rpmpkgs* samba/* sa/* scrollkeeper.log secure* spooler* squid/* vbox/* wtmp
chmod o-rx boot.log* cron* maillog* messages* pgsql secure* spooler* squid/* sa/*
chmod g-w boot.log* cron* dmesg httpd/* ksyms* maillog* messages* pgsql rpmpkgs* samba/* sa/* scrollkeeper.log secure* spooler*
chmod g-rx boot.log* cron* maillog* messages* pgsql secure* spooler*
chmod o-w gdm/ httpd/ news/ samba/ squid/ sa/ vbox/
chmod o-rx httpd/ samba/ squid/ sa/
chmod g-w gdm/ httpd/ news/ samba/ squid/ sa/ vbox/
chmod g-rx httpd/ samba/ sa/
chmod u-x kernel syslog loginlog
# Verify passwd, shadow, and group File Permissions
cd /etc
chown root:root passwd shadow group
chmod 644 passwd group
chmod 400 shadow
# Allowing only root access to Cron and At
cd /etc/
rm -f cron.deny at.deny
echo root > cron.allow
echo root > at.allow
chown root:root cron.allow at.allow
chmod 400 cron.allow at.allow
# Restrict Permissions On crontab Files
chown root:root /etc/crontab
chmod 400 /etc/crontab
chown -R root:root /var/spool/cron
chmod -R go-rwx /var/spool/cron
cd /etc
ls | grep cron | grep -v preCIS | xargs chown -R root:root
ls | grep cron | grep -v preCIS | xargs chmod -R go-rwx
# Block all system accounts from loging on to the server
cd /root
vi lock_system_accounts
####
cd /etc
for NAME in `cut -d: -f1 /etc/passwd`; do
MyUID=`id -u $NAME`
if [ $MyUID -lt 500 -a $NAME != 'root' ]; then
/usr/sbin/usermod -L -s /dev/null $NAME
fi
done
###
chmod 755 lock_system_accounts
./lock_system_accounts
rm -rf lock_system_accounts
# Check for empty password accounts
awk -F: '($2 == "") { print $1 }' /etc/shadow
# Set Account Expiration Parameters On Active Accounts
cd /etc
awk '($1 ~ /^PASS_MAX_DAYS/) { $2="90" }
($1 ~ /^PASS_MIN_DAYS/) { $2="7" }
($1 ~ /^PASS_WARN_AGE/) { $2="28" }
($1 ~ /^PASS_MIN_LEN/) { $2="6" }
{ print } ' login.defs-preCIS > login.defs
diff login.defs-preCIS login.defs
chown root:root login.defs
chmod 640 login.defs
diff login.defs-preCIS login.defs
useradd -D -f 7
diff /etc/default/useradd-preCIS /etc/default/useradd
for NAME in `cut -d: -f1 /etc/passwd`; do
uid=`id -u $NAME`
if [ $uid -ge 500 -a $uid != 65534 ]; then
chage -m 7 -M 90 -W 28 -I 7 $NAME
fi
done
diff shadow-preCIS shadow
# Verify No Legacy '+' Entries Exist In passwd, shadow, And group Files
grep ^+: /etc/passwd /etc/shadow /etc/group
# No '.' or Group/World-Writable Directory In Root's $PATH
#To find ‘.’ in $PATH:
echo $PATH | egrep '(^|:)(\.|:|$)'
#To find group- or world-writable directories in $PATH:
find `echo $PATH | tr ':' ' '` -type d \( -perm -002 -o -perm -020 \) -ls
#These commands should produce no output.
#User Home Directories Should Be Mode 750 or More Restrictive
vi user_directories_permission
###############
for DIR in `awk -F: '($3 >= 500) { print $6 }' /etc/passwd`; do
chmod g-w $DIR
chmod o-rwx $DIR
done
##############
chmod 755 user_directories_permission
./user_directories_permission
#No User Dot-Files Should Be World-Writable
vi user_dot_files_non_worldwritable
#############
for DIR in `awk -F: '($3 >= 500) { print $6 }' /etc/passwd`; do
for FILE in $DIR/.[A-Za-z0-9]*; do
if [ ! -h "$FILE" -a -f "$FILE" ]; then
chmod go-w "$FILE"
fi
done
done
#########
chmod 755 user_dot_files_non_worldwritable
./user_dot_files_non_worlwritable
#Remove User .netrc Files
find / -name .netrc
# If any .netrc file is found then run the following script to remove
vi remove_netrc
###############
for DIR in `cut -f6 -d: /etc/passwd`; do
if [ -e $DIR/.netrc ]; then
echo "Removing $DIR/.netrc"
rm -f $DIR/.netrc fi
done
###############
chmod 755 remove_netrc
./remove_netrc
#Set Default umask For Users
vi set_default_umask
#########
cd /etc
for FILE in profile csh.login csh.cshrc bashrc; do
if ! egrep -q 'umask.*77' $FILE ; then
echo "umask 077" >> $FILE
fi
chown root:root $FILE
chmod 444 $FILE
diff ${FILE}-preCIS $FILE
done
cd /root
for FILE in .bash_profile .bashrc .cshrc .tcshrc; do
if ! egrep -q 'umask.*77' $FILE ; then
echo "umask 077" >> $FILE # See description
fi
chown root:root $FILE
diff ${FILE}-preCIS $FILE
done
###########
chmod 755 set_default_umask
./set_default_umask
# Disable Core Dumps
cp -a /etc/security/limits.conf /etc/security/limits.conf.orig
vi /etc/security/limits.conf
#Add the following two lines.In future you can enable core dumps for invidual users if required.
* soft core 0
* hard core 0
####
# Limit Access To The Root Account From su
# Warning:Please add your account to the wheel group before proceeding with this activity else you # will not be able to su.
# eg. /usr/sbin/usermod -G wheel
# In case you want to create a new account and add it to the wheel group, then run this command
/usr/sbin/useradd -G wheel
# Limit Access To The Root Account From su
cd /etc/pam.d/
cp -a su su_backup_18_dec_2006
vi su
##Uncommenting this line allows only the users in the wheel group to become root by using the su command and entering the root password.All other users get the message Incorrect Password
auth required /lib/security/$ISA/pam_wheel.so use_uid
# Banners
# Note:/etc/issue banner should have already been created by BastilleIf you havent run Bastille please create an appropriate banner file /etc/issue as follows
***************************************************************************
NOTICE TO USERS
This computer system is the private property of
individual, corporate or government. It is for authorized use only.
Users (authorized or unauthorized) have no explicit or implicit
expectation of privacy.
Any or all uses of this system and all files on this system may be
intercepted, monitored, recorded, copied, audited, inspected, and
disclosed to your employer, to authorized site, government, and law
enforcement personnel, as well as authorized officials of government
agencies, both domestic and foreign.
By using this system, the user consents to such interception, monitoring,
recording, copying, auditing, inspection, and disclosure at the
discretion of such personnel or officials. Unauthorized or improper use
of this system may result in civil and criminal penalties and
administrative or disciplinary action, as appropriate. By continuing to use
this system you indicate your awareness of and consent to these terms
and conditions of use. LOG OFF IMMEDIATELY if you do not agree to the
conditions stated in this warning.
****************************************************************************
cp -a issue.net issue_backup_todays_date.net
cp -a issue issue.net
# Contents of /etc/motd are displayed after a user logins in so its not neccessary to create a #banner in that file
chown root:root /etc/motd /etc/issue /etc/issue.net
chmod 644 /etc/motd /etc/issue /etc/issue.net
# Removing unnecessary applications
# Please refer http://www.mjmwired.net/resources/mjm-services-fc6.html for the list of services and their uses and recommendations on which to disable
cd /etc/init.d
ls
# Verify the softwares that are listed here.Remove all unnecesaasy packages as show below.
# For eg. if you see bluetooth and you want to identify what package it represnts, do the following
rpm -qf bluetooth
bluez-utils-2.15-7
yum remove bluez-utils-2.15-7
# Do this for all other softwares like portmap,apmd,cups,isdn,irda,etc.
# RHEL comes with virtualisation enabled.Due to this you may see an additional network adapter ( virbr0 ) when you run /sbin/ifconfig -a
# This can be removed by following these steps
#Source :http://www.cyberciti.biz/faq/rhel-fedora-centos-linux-remove-network-interface-virbr0/
yum groupremove "Virtualization"
# Type y when it lists the following pakcages to be removed
libvirt
libvirt-python
rhn-virtualization-host
This will also remove the virbr0 network adapter
#Firewall Configuration
/bin/netstat -ltunp
# The above command will show you list of processes running on specific ports.Please ensure that unnecassary services are disabled and uninstalled as shown in the above point.
# Open required ports in iptables using Shorewall (Please refer the separate Howto)
/usr/sbin/lokkit
# Remove All Compilers and Assemblers
#The following command will help you identify the packages installed on your system
rpm -qa | egrep "^gcc|java|bin86|dev86|nasm"
#Identify the package and remove the ones you dont need
#Verify That No Unauthorized UID 0 Accounts Exists
getent passwd | awk -F: '$3 == "0" { print $1 }'
#should return only the word "root", unless additional uid 0 accounts have been specifically authorized. Having #multiple uid 0 accounts are acceptable if the accounts are authorized, but not recommended for some situations.
Reactive Firewall Setup using Psad
Reference: http://www.cipherdyne.org/psad/
# Download the latest version of psad from http://www.cipherdyne.org/psad/download/
cd /tmp
wget http://www.cipherdyne.org/psad/download/psad-2.1.4-1.i386.rpm
rpm -Uvh psad-2.1.4-1.i386.rpm
rm -rf psad-2.1.4-1.i386.rpm
cp -a /etc/psad/psad.conf /etc/psad/psad.conf.orig
vi /etc/psad/psad.conf
# Adjust the values as shown
######
EMAIL_ADDRESSES you@domain1.com, you@domain2.com;
HOSTNAME example.com;
# If there is only one network interface on the box, then just set this variable to "NOT_USED".
HOME_NET NOT_USED;
EMAIL_ALERT_DANGER_LEVEL 1;
ENABLE_AUTO_IDS Y;
AUTO_IDS_DANGER_LEVEL 1;
ENABLE_SCAN_ARCHIVE Y;
DISK_MAX_PERCENTAGE 85;
FLUSH_IPT_AT_INIT N;
#######
# Add CIDR value of a private network interface card in HOME_NET if you are using one.Not required if you have a single public interface.
Automate Signature Updates
crontab -e
###
0 0 * * * /usr/sbin/psad --sig-update && /sbin/service psad restart
###
# Ensure that /bin/mail exists or create an appropriate symbolic link /bin/mail poiting to your mail executable
eg.
ln -s /usr/lib/sendmail /bin/mail
/etc/rc.d/init.d/psad start
/usr/sbin/psad --sig-update
/sbin/chkconfig psad on
# Check psad statistics after 5-10 mins by running this command
/usr/sbin/psad --Status
# Setup Cronjob to delete Psad scan archive older than 7 days
crontab -e
0 0 * * * find /var/log/psad/scan_archive -type d -mtime +7 | xargs rm -rf
# Fwsnort Installation
Reference: http://www.cipherdyne.org/fwsnort
# Download fwsnort from http://www.cipherdyne.org/fwsnort/download/
cd /tmp
wget http://www.cipherdyne.org/fwsnort/download/fwsnort-1.0.5.tar.gz
tar zxvf fwsnort-1.0.5.tar.gz
cd /tmp/fwsnort-1.0.5
perl install.pl
cp -a /etc/fwsnort/fwsnort.conf /etc/fwsnort/fwsnort.conf.orig
vi /etc/fwsnort/fwsnort.conf
######
# Modify the uname location as follows
unameCmd /bin/uname;
######
# Add CIDR value of a private network interface card in HOME_NET in /etc/fwsnort/fwsnort.conf if you are using one.Not required if you have a single public interface.
/usr/sbin/fwsnort --no-ipt-sync --verbose
# Check log file for errors and correct accordingly
tail -f /var/log/fwsnort.log
#If you encounter the following errors
###
#[*] It does not appear that string match support has been compiled into
# Netfilter. Fwsnort will not be of very much use without this.
# ** NOTE: If you want to have fwsnort generate a Netfilter policy
# anyway, specify the --no-ipt-test option. Exiting.
#[root@extranet tmp]# tail -f /var/log/fwsnort.log
#[-] Netfilter ipv4options extension not available, disabling ipopts translation.
# then run this
# Update signatures
/usr/sbin/fwsnort --update-rules
#Then run this
/usr/sbin/fwsnort --no-ipt-test --verbose
# Run the generated Netfilter script
/etc/fwsnort/fwsnort.sh
# Enable auto-update of firewall rules
crontab -e
1 1 * * * /usr/sbin/fwsnort --no-ipt-test --verbose > /dev/null 2>&1 && sh /etc/fwsnort/fwsnort.sh > /dev/null 2>&1
# Enable auto-update of fwsnort signatures
crontab -e
0 0 * * * /usr/sbin/fwsnort --update-rules
/etc/rc.d/init.d/psad restart
rm -rf /tmp/fwsnort-1.0.5.tar.gz
rm -rf /tmp/fwsnort-1.0.5
# Enabling whitelisting and Special danger levels for IPs and Port.
Edit the /etc/psad/auto_dl for whitelisting or setting up an elevated danger zone.
# Eg. Add the IP address of the nmap/nessus server in the /etc/psad/auto_dl file before starting the nessus scan.Please ensure that you restart psad after adding the IP address.
# Download the latest version of psad from http://www.cipherdyne.org/psad/download/
cd /tmp
wget http://www.cipherdyne.org/psad/download/psad-2.1.4-1.i386.rpm
rpm -Uvh psad-2.1.4-1.i386.rpm
rm -rf psad-2.1.4-1.i386.rpm
cp -a /etc/psad/psad.conf /etc/psad/psad.conf.orig
vi /etc/psad/psad.conf
# Adjust the values as shown
######
EMAIL_ADDRESSES you@domain1.com, you@domain2.com;
HOSTNAME example.com;
# If there is only one network interface on the box, then just set this variable to "NOT_USED".
HOME_NET NOT_USED;
EMAIL_ALERT_DANGER_LEVEL 1;
ENABLE_AUTO_IDS Y;
AUTO_IDS_DANGER_LEVEL 1;
ENABLE_SCAN_ARCHIVE Y;
DISK_MAX_PERCENTAGE 85;
FLUSH_IPT_AT_INIT N;
#######
# Add CIDR value of a private network interface card in HOME_NET if you are using one.Not required if you have a single public interface.
Automate Signature Updates
crontab -e
###
0 0 * * * /usr/sbin/psad --sig-update && /sbin/service psad restart
###
# Ensure that /bin/mail exists or create an appropriate symbolic link /bin/mail poiting to your mail executable
eg.
ln -s /usr/lib/sendmail /bin/mail
/etc/rc.d/init.d/psad start
/usr/sbin/psad --sig-update
/sbin/chkconfig psad on
# Check psad statistics after 5-10 mins by running this command
/usr/sbin/psad --Status
# Setup Cronjob to delete Psad scan archive older than 7 days
crontab -e
0 0 * * * find /var/log/psad/scan_archive -type d -mtime +7 | xargs rm -rf
# Fwsnort Installation
Reference: http://www.cipherdyne.org/fwsnort
# Download fwsnort from http://www.cipherdyne.org/fwsnort/download/
cd /tmp
wget http://www.cipherdyne.org/fwsnort/download/fwsnort-1.0.5.tar.gz
tar zxvf fwsnort-1.0.5.tar.gz
cd /tmp/fwsnort-1.0.5
perl install.pl
cp -a /etc/fwsnort/fwsnort.conf /etc/fwsnort/fwsnort.conf.orig
vi /etc/fwsnort/fwsnort.conf
######
# Modify the uname location as follows
unameCmd /bin/uname;
######
# Add CIDR value of a private network interface card in HOME_NET in /etc/fwsnort/fwsnort.conf if you are using one.Not required if you have a single public interface.
/usr/sbin/fwsnort --no-ipt-sync --verbose
# Check log file for errors and correct accordingly
tail -f /var/log/fwsnort.log
#If you encounter the following errors
###
#[*] It does not appear that string match support has been compiled into
# Netfilter. Fwsnort will not be of very much use without this.
# ** NOTE: If you want to have fwsnort generate a Netfilter policy
# anyway, specify the --no-ipt-test option. Exiting.
#[root@extranet tmp]# tail -f /var/log/fwsnort.log
#[-] Netfilter ipv4options extension not available, disabling ipopts translation.
# then run this
# Update signatures
/usr/sbin/fwsnort --update-rules
#Then run this
/usr/sbin/fwsnort --no-ipt-test --verbose
# Run the generated Netfilter script
/etc/fwsnort/fwsnort.sh
# Enable auto-update of firewall rules
crontab -e
1 1 * * * /usr/sbin/fwsnort --no-ipt-test --verbose > /dev/null 2>&1 && sh /etc/fwsnort/fwsnort.sh > /dev/null 2>&1
# Enable auto-update of fwsnort signatures
crontab -e
0 0 * * * /usr/sbin/fwsnort --update-rules
/etc/rc.d/init.d/psad restart
rm -rf /tmp/fwsnort-1.0.5.tar.gz
rm -rf /tmp/fwsnort-1.0.5
# Enabling whitelisting and Special danger levels for IPs and Port.
Edit the /etc/psad/auto_dl for whitelisting or setting up an elevated danger zone.
# Eg. Add the IP address of the nmap/nessus server in the /etc/psad/auto_dl file before starting the nessus scan.Please ensure that you restart psad after adding the IP address.
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