How to Install Mod Security on Linux Centos 5.4, Fedora 11-12

ModSecurity is a free open source Firewall for Web application which can help you to guard against Intrusion on your webservers like local file inclusion attacks, Cross Site Scripting, and SQL injection vulnerabilities and many more.

The easiest way to install mod_security is using yum, to get the latest package of modsecurity refer to jason litka rpms.
Lets Start

Install the gpg Key

You need to be Root to run this:

[ashwin@ashwin ~]$ rpm –import http://www.jasonlitka.com/media/RPM-GPG-KEY-jlitka

Create a File

[ashwin@ashwin ~]$ touch /etc/yum.repos.d/utterramblings.repo

Open the File using your favorite editor and add the contents

[ashwin@ashwin ~]$ vim /etc/yum.repos.d/utterramblings.repo

[utterramblings]
name=Jason’s Utter Ramblings Repo
baseurl=http://www.jasonlitka.com/media/EL$releasever/$basearch/
enabled=1
gpgcheck=1
gpgkey=http://www.jasonlitka.com/media/RPM-GPG-KEY-jlitka

Save the File and exit

Now you can Install Mod-Security

[root@ashwin ~]# yum install mod_security
Setting up Install Process
Parsing package install arguments
Resolving Dependencies
--> Running transaction check
---> Package mod_security.i386 0:2.5.9-1.jason.1 set to be updated
--> Finished Dependency Resolution

Dependencies Resolved

=============================================================================
Package                 Arch       Version          Repository        Size
=============================================================================
Installing:
mod_security            i386       2.5.9-1.jason.1  utterramblings    1.2 M

Transaction Summary
=============================================================================
Install      1 Package(s)
Update       0 Package(s)
Remove       0 Package(s)

Total download size: 1.2 M
Is this ok [y/N]: y
Downloading Packages:
(1/1): mod_security-2.5.9 100% |=========================| 1.2 MB    00:03
warning: rpmts_HdrFromFdno: Header V3 DSA signature: NOKEY, key ID 0d4306ef
Importing GPG key 0x0D4306EF "Jason Litka (http://www.jasonlitka.com) <jasonlitka@verizon.net>" from http://www.jasonlitka.com/media/RPM-GPG-KEY-jlitka
Is this ok [y/N]: y
Running rpm_check_debug
Running Transaction Test
Finished Transaction Test
Transaction Test Succeeded
Running Transaction
Installing: mod_security                 ######################### [1/1]

Installed: mod_security.i386 0:2.5.9-1.jason.1
Complete!

Great You have installed mod security Restart HTTPD service and Roll. Check the Logs and you will find the magic.

Issues :

1. Starting httpd: httpd: Syntax error on line 210 of /etc/httpd/conf/httpd.conf: Syntax error on line 3 of /etc/httpd/conf.d/mod_security.conf: Cannot load /etc/httpd/modules/mod_security2.so into server: /etc/httpd/modules/mod_security2.so: undefined symbol: ap_get_server_banner

Solution :

[root@ashwin ~]#  yum remove httpd mod_perl mod_perl-devel mod_security
[root@ashwin ~]#  mv /etc/yum.repos.d/CentOS-Base.repo /tmp ( move base centos repo to /tmp )
[root@ashwin ~]#  yum install httpd ( This will install apache from utterramblings.repo )
[root@ashwin ~]#  yum install mod_perl mod_perl-devel
[root@ashwin ~]#  yum install mod_security

Step by Step Installing mod_security from Source in Linux Centos5.4, Fedora12 Howto

To Install mod Security from the source go to the Website of Mod security and download the packages

[superuser@ashwin modse]# get http://www.modsecurity.org/download/modsecurity-apache_2.5.12.tar.gz

--2010-05-05 15:19:12--  http://www.modsecurity.org/download/modsecurity-apache_2.5.12.tar.gz

Saving to: `modsecurity-apache_2.5.12.tar.gz'

100%[=======================================>] 1,392,209   1235.9Mb/s   in 5s     

2010-05-05 15:19:18 (1235.7 MB/s) - `modsecurity-apache_2.5.12.tar.gz' saved [1392209/1392209]

[superuser@ashwin modse]#  tar -zxf modsecurity-apache_2.5.12.tar.gz
[superuser@ashwin modse]# cd modsecurity-apache_2.5.12

Stop Apache httpd

[superuser@ashwin modse]# service httpd stop
[superuser@ashwin apache2]# /configure --with-apxs=/path/to/httpd-2.x.y/bin/apxs

Compile with:

[superuser@ashwin apache2]# make

Optionally test with:

[superuser@ashwin apache2]# make test

Optionally build the ModSecurity Log Collector with:

[superuser@ashwin apache2]# make mlogc

Install the ModSecurity module with:

[superuser@ashwin apache2]# make install

If you get the below error you need to recompile apache with DSO and APXS

configure: looking for Apache module support via DSO through APXS
configure: error: couldn't find APXS

Solution

[superuser@ashwin modse]# get http://apache.siamwebhosting.com/httpd/httpd-2.2.15.tar.gz
[superuser@ashwin modse]# cd httpd-2.2.15
[superuser@ashwin httpd-2.2.15]# ./configure --enable-so  --with-pcre
[superuser@ashwin httpd-2.2.15]# make
[superuser@ashwin httpd-2.2.15]# make install

Now Change you directory to /your/path/mod-security/apache2/
Install MOD-Security

[superuser@ashwin apache2]# make install

Congratulation you have successfully installed mod-security now to make it work add the following lines in your apache configuration file

[superuser@ashwin apache2]# vi /etc/httpd/conf/httpd.conf
LoadFile /usr/lib/libxml2.so
LoadFile /usr/lib/liblua5.1.so

# Load the ModSecurity module with:
LoadModule security2_module modules/mod_security2.so

Now Restart Apache Service and you ready to Go

superuser@ashwin apache2]# service httpd start

How to Enable htaccess in Apache?

What is htaccess?
Htaccess files are files containing single or several configuration apache directives, which should be placed inside the web directory where changes have to made and all its sub directories.

The easient way to enable .htaccess file in apache is tp add the following in the Apache / HTTPD conf, Uncomment the below line and restart apache. You need to enable rewrite module

#LoadModule rewrite_module modules/mod_rewrite.so to

LoadModule rewrite_module modules/mod_rewrite.so

Add this to the Apache Main Configuration.
AccessFileName .htaccess
.htaccess file can have different name just specify the name following
AccessFileName your_htaccess_file_name

Pros
Useful when Administrators, Developers, requires to make configuration changes on per directory basis
Useful for ISP and Webhosting providers to permit multiple users running multiple sites on the same server to change thier own htaccess file.

Cons
Never use .htaccess files if you dont have the access to the Server Configuration File.
Uses Need to have root or Super User access to edit the main configuration file in apache.
Never Use user authetication in htaccess file instead do it in the Apache Main Configuration.
AllowOverride when set to allow apache will search for .htaccess file in every directory which would lead in poor performance of the webserver.

Directives in a .htaccess file

SSI (Server Side includes .htaccess file) Samples

Options +Includes
AddType text/html shtml
AddHandler server-parsed shtml


CGI Samples

Options +ExecCGI
AddHandler cgi-script cgi pl

Live Examples :


Options FollowSymLinks
AllowOverride All
Order deny,allow
Deny from all
Satisfy all