1. Always use latest stable XOOPS core.
2. Keep your modules updated to the latest stable release.
3. The .htaccess file
Remote File Inclusion Protection
RewriteEngine On
RewriteBase /
RewriteCond %{QUERY_STRING} ^.*=(ht)|(f)+(tp)+(://|s://)+.*(??)+
RewriteRule .* http://your-trap.com/php-trap-script.php [R,L]
Various protections
# Block out any script trying to base64_encode crap to send via URL
RewriteCond %{QUERY_STRING} base64_encode.*(.*) [OR]
# Block out any script that includes a <script> tag in URL
RewriteCond %{QUERY_STRING} (<|%3C).*script.*(>|%3E) [NC,OR]
# Block out any script trying to set a PHP GLOBALS variable via URL
RewriteCond %{QUERY_STRING} GLOBALS(=|[|%[0-9A-Z]{0,2}) [OR]
# Block out any script trying to modify a _REQUEST variable via URL
RewriteCond %{QUERY_STRING} _REQUEST(=|[|%[0-9A-Z]{0,2})
# Send all blocked request to homepage with 403 Forbidden error!
RewriteRule ^(.*)$ index.php [F,L]
Disallow displaying content of folders which don't have index.html within
Options +FollowSymLinks -Indexes
Next 2 must be added directly after RewriteEngine On
Blocking Download Managers and Proxies
RewriteCond %{HTTP:VIA} !^$ [OR]
RewriteCond %{HTTP:FORWARDED} !^$ [OR]
RewriteCond %{HTTP:USERAGENT_VIA} !^$ [OR]
RewriteCond %{HTTP:X_FORWARDED_FOR} !^$ [OR]
RewriteCond %{HTTP:PROXY_CONNECTION} !^$ [OR]
RewriteCond %{HTTP:XPROXY_CONNECTION} !^$ [OR]
RewriteCond %{HTTP:HTTP_PC_REMOTE_ADDR} !^$ [OR]
RewriteCond %{HTTP:XROXY_CONNECTION} !^$ [OR]
RewriteCond %{HTTP:X-FORWARDED-FOR} !^$ [OR]
RewriteCond %{HTTP:FORWARDED-FOR} !^$ [OR]
RewriteCond %{HTTP:X-FORWARDED} !^$ [OR]
RewriteCond %{HTTP:HTTP_CLIENT_IP} !^$
RewriteRule ^(.*)$ - [F]
Blocking Bad Robots
RewriteCond %{HTTP_USER_AGENT} ^BlackWidow [OR]
RewriteCond %{HTTP_USER_AGENT} ^Bot mailto:craftbot@yahoo.com [OR]
RewriteCond %{HTTP_USER_AGENT} ^ChinaClaw [OR]
RewriteCond %{HTTP_USER_AGENT} ^Custo [OR]
RewriteCond %{HTTP_USER_AGENT} ^DISCo [OR]
RewriteCond %{HTTP_USER_AGENT} ^Download Demon [OR]
RewriteCond %{HTTP_USER_AGENT} ^eCatch [OR]
RewriteCond %{HTTP_USER_AGENT} ^EirGrabber [OR]
RewriteCond %{HTTP_USER_AGENT} ^EmailSiphon [OR]
RewriteCond %{HTTP_USER_AGENT} ^EmailWolf [OR]
RewriteCond %{HTTP_USER_AGENT} ^Express WebPictures [OR]
RewriteCond %{HTTP_USER_AGENT} ^ExtractorPro [OR]
RewriteCond %{HTTP_USER_AGENT} ^EyeNetIE [OR]
RewriteCond %{HTTP_USER_AGENT} ^FlashGet [OR]
RewriteCond %{HTTP_USER_AGENT} ^GetRight [OR]
RewriteCond %{HTTP_USER_AGENT} ^GetWeb! [OR]
RewriteCond %{HTTP_USER_AGENT} ^Go!Zilla [OR]
RewriteCond %{HTTP_USER_AGENT} ^Go-Ahead-Got-It [OR]
RewriteCond %{HTTP_USER_AGENT} ^GrabNet [OR]
RewriteCond %{HTTP_USER_AGENT} ^Grafula [OR]
RewriteCond %{HTTP_USER_AGENT} ^HMView [OR]
RewriteCond %{HTTP_USER_AGENT} HTTrack [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^Image Stripper [OR]
RewriteCond %{HTTP_USER_AGENT} ^Image Sucker [OR]
RewriteCond %{HTTP_USER_AGENT} Indy Library [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^InterGET [OR]
RewriteCond %{HTTP_USER_AGENT} ^Internet Ninja [OR]
RewriteCond %{HTTP_USER_AGENT} ^JetCar [OR]
RewriteCond %{HTTP_USER_AGENT} ^JOC Web Spider [OR]
RewriteCond %{HTTP_USER_AGENT} ^larbin [OR]
RewriteCond %{HTTP_USER_AGENT} ^LeechFTP [OR]
RewriteCond %{HTTP_USER_AGENT} ^Mass Downloader [OR]
RewriteCond %{HTTP_USER_AGENT} ^MIDown tool [OR]
RewriteCond %{HTTP_USER_AGENT} ^Mister PiX [OR]
RewriteCond %{HTTP_USER_AGENT} ^Navroad [OR]
RewriteCond %{HTTP_USER_AGENT} ^NearSite [OR]
RewriteCond %{HTTP_USER_AGENT} ^NetAnts [OR]
RewriteCond %{HTTP_USER_AGENT} ^NetSpider [OR]
RewriteCond %{HTTP_USER_AGENT} ^Net Vampire [OR]
RewriteCond %{HTTP_USER_AGENT} ^NetZIP [OR]
RewriteCond %{HTTP_USER_AGENT} ^Octopus [OR]
RewriteCond %{HTTP_USER_AGENT} ^Offline Explorer [OR]
RewriteCond %{HTTP_USER_AGENT} ^Offline Navigator [OR]
RewriteCond %{HTTP_USER_AGENT} ^PageGrabber [OR]
RewriteCond %{HTTP_USER_AGENT} ^Papa Foto [OR]
RewriteCond %{HTTP_USER_AGENT} ^pavuk [OR]
RewriteCond %{HTTP_USER_AGENT} ^pcBrowser [OR]
RewriteCond %{HTTP_USER_AGENT} ^RealDownload [OR]
RewriteCond %{HTTP_USER_AGENT} ^ReGet [OR]
RewriteCond %{HTTP_USER_AGENT} ^SiteSnagger [OR]
RewriteCond %{HTTP_USER_AGENT} ^SmartDownload [OR]
RewriteCond %{HTTP_USER_AGENT} ^SuperBot [OR]
RewriteCond %{HTTP_USER_AGENT} ^SuperHTTP [OR]
RewriteCond %{HTTP_USER_AGENT} ^Surfbot [OR]
RewriteCond %{HTTP_USER_AGENT} ^tAkeOut [OR]
RewriteCond %{HTTP_USER_AGENT} ^Teleport Pro [OR]
RewriteCond %{HTTP_USER_AGENT} ^VoidEYE [OR]
RewriteCond %{HTTP_USER_AGENT} ^Web Image Collector [OR]
RewriteCond %{HTTP_USER_AGENT} ^Web Sucker [OR]
RewriteCond %{HTTP_USER_AGENT} ^WebAuto [OR]
RewriteCond %{HTTP_USER_AGENT} ^WebCopier [OR]
RewriteCond %{HTTP_USER_AGENT} ^WebFetch [OR]
RewriteCond %{HTTP_USER_AGENT} ^WebGo IS [OR]
RewriteCond %{HTTP_USER_AGENT} ^WebLeacher [OR]
RewriteCond %{HTTP_USER_AGENT} ^WebReaper [OR]
RewriteCond %{HTTP_USER_AGENT} ^WebSauger [OR]
RewriteCond %{HTTP_USER_AGENT} ^Website eXtractor [OR]
RewriteCond %{HTTP_USER_AGENT} ^Website Quester [OR]
RewriteCond %{HTTP_USER_AGENT} ^WebStripper [OR]
RewriteCond %{HTTP_USER_AGENT} ^WebWhacker [OR]
RewriteCond %{HTTP_USER_AGENT} ^WebZIP [OR]
RewriteCond %{HTTP_USER_AGENT} ^Wget [OR]
RewriteCond %{HTTP_USER_AGENT} ^Widow [OR]
RewriteCond %{HTTP_USER_AGENT} ^WWWOFFLE [OR]
RewriteCond %{HTTP_USER_AGENT} ^Xaldon WebSpider [OR]
RewriteCond %{HTTP_USER_AGENT} ^Zeus
RewriteRule .* - [F]
The following 4 lines
RewriteCond %{HTTP:VIA} !^$ [OR]
RewriteCond %{HTTP:FORWARDED} !^$ [OR]
RewriteCond %{HTTP:USERAGENT_VIA} !^$ [OR]
RewriteCond %{HTTP:X_FORWARDED_FOR} !^$ [OR]
blocks the access to services such as Facebook and Google Translate, if u don't comment them out.
Check that all files are with permissions 644 and folders with permissions 755.
The following lines must be added in php.ini and placed in your XOOPS root folder
register_globals=Off
safe_mode=Off
allow_url_fopen=Off
allow_url_include=Off
disable_functions=show_source, system, shell_exec, passthru, exec, phpinfo, popen, proc_open
open_basedir=/home/some_path/public_html
safe_mode - must be Off.
safe_mode is a security risk; it was supposed to add a new layer of security to PHP, but it ended up creating more bugs.
allow_url_fopen - must be Off
allow_url_fopen might allow an attacker to include his own PHP scripts in your XOOPS website, ultimately taking control of the webserver.
allow_url_include - must be Off
allow_url_include might allow an attacker to include his own PHP scripts in your XOOPS website, ultimately taking control of the webserver.
disable_functions - recommended to be used
disable_functions disables dangerous PHP functions. It is recommended to disable: show_source, system, shell_exec, passthru, exec, phpinfo, popen, proc_open
open_basedir - recommended to be used. open_basedir restricts access to specified directories only.
Do not use administrator user name such as: admin, administrator, root. Make password with random chars.
Do not install modules which are from:
Dead authors
Abandoned
Not Trusted Sites
Not Trusted Authors
IP Blocking:
Use
deny from 111.222.333.444
For blocking specific IP Address Range
or
deny from 111.222.333.0-111.222.333.255
[EDIT by Mamba]
Using
IP2Country IP Address List you can ban those countries from which you're receiving most spam in your Website, or which are historically known for spam activities, and your Website is not interested in traffic from them
[/EDIT]
(Some more stuff will be added later.... XOOPS should be changed a bit too)
Edit: Proposed PHP.INI may conflict with some XOOPS installs.