How do I disable mod_security or solve 406 errors for a Website

quick setup.

edit your .httacces files on the web location and add the following lines,

<IfModule mod_security.c>
SecFilterEngine Off
SecFilterScanPOST Off
</IfModule>

Secure Webserver from Php function vulernability

PHP has a lot of functions which can be used to crack your server if not used properly. You can set list of functions in php.ini using disable_functions directive. This directive allows you to disable certain functions for security reasons. It takes on a comma-delimited list of function names. disable_functions is not affected by Safe Mode. This directive must be set in php.ini For example, you cannot set this in httpd.conf.

Open php.ini file:
# vi /etc/php.ini
Find disable_functions and set new list as follows:
disable_functions =exec,passthru,shell_exec,system,proc_open,popen,curl_exec,curl_multi_exec,parse_ini_file,show_source
Save and close the file. Restart httpd:
# service httpd restart