below is the steps to install Mod_security in Centos Linux server
1- # yum install mod_security
2- you should see the below
Loaded plugins: downloadonly, fastestmirror, priorities, protectbase
Loading mirror speeds from cached hostfile
* epel: www.gtlib.gatech.edu
* base: mirror.skiplink.com
* updates: centos.aol.com
* addons: mirror.cs.vt.edu
* extras: mirror.trouble-free.net
0 packages excluded due to repository protections
Setting up Install Process
Parsing package install arguments
Resolving Dependencies
--> Running transaction check
---> Package mod_security.x86_64 0:2.5.9-1.el5 set to be updated
--> Finished Dependency Resolution
Dependencies Resolved
==============================================================================================================================================================
Package Arch Version Repository Size
==============================================================================================================================================================
Installing:
mod_security x86_64 2.5.9-1.el5 epel 935 k
Transaction Summary
==============================================================================================================================================================
Install 1 Package(s)
Update 0 Package(s)
Remove 0 Package(s)
Total download size: 935 k
Is this ok [y/N]: y
Downloading Packages:
mod_security-2.5.9-1.el5.x86_64.rpm | 935 kB 00:00
Running rpm_check_debug
Running Transaction Test
Finished Transaction Test
Transaction Test Succeeded
Running Transaction
Installing : mod_security [1/1]
Installed: mod_security.x86_64 0:2.5.9-1.el5
Complete!
vi /etc/httpd/modsecurity.d/modsecurity_crs_10_config.conf
make sure this is one
SecRuleEngine On
service httpd restart
tail -f /var/log/httpd/error_log
simple out put
[Sat May 09 23:18:31 2009] [notice] caught SIGTERM, shutting down
[Sat May 09 23:18:33 2009] [notice] suEXEC mechanism enabled (wrapper: /usr/sbin/suexec)
[Sat May 09 23:18:34 2009] [notice] ModSecurity for Apache/2.5.9 (http://www.modsecurity.org/) configured.
[Sat May 09 23:18:34 2009] [notice] Original server signature: Apache/2.2.3 (CentOS)
[Sat May 09 23:18:34 2009] [notice] Digest: generating secret for digest authentication ...
[Sat May 09 23:18:34 2009] [notice] Digest: done
[Sat May 09 23:18:35 2009] [notice] Apache/2.2.0 (Fedora) configured -- resuming normal operations
Thank you