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## QUERY STRING / HTTP METHOD BLOCKS ##
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#request query string contains base64_encode / base64_decode
RewriteCond %{QUERY_STRING} base64_(en|de)code[^(]*\([^)]*\) [NC,OR]
# Block <script> in query string
RewriteCond %{QUERY_STRING} (<|%3C)([^s]*s)+cript.*(>|%3E) [NC,OR]
# Block out any script trying to modify a _REQUEST variable via URL
RewriteCond %{QUERY_STRING} _REQUEST(=|\[|\%[0-9A-Z]{0,2}) [NC,OR]
# Prevent use of specified methods in HTTP Request 
RewriteCond %{REQUEST_METHOD} ^(HEAD|TRACE|DELETE|TRACK) [NC,OR] 
# Block out use of illegal or unsafe characters in the HTTP Request 
RewriteCond %{THE_REQUEST} ^.*(\\r|\\n|%0A|%0D).* [NC,OR] 
# Block out use of illegal or unsafe characters in the Referer Variable of the HTTP Request 
RewriteCond %{HTTP_REFERER} ^(.*)(<|>|'|%0A|%0D|%27|%3C|%3E|%00).* [NC,OR] 
# Block out use of illegal or unsafe characters in any cookie associated with the HTTP Request 
RewriteCond %{HTTP_COOKIE} ^.*(<|>|'|%0A|%0D|%27|%3C|%3E|%00).* [NC,OR] 
# Block out use of illegal characters in URI or use of malformed URI 
RewriteCond %{REQUEST_URI} ^/(,|;|:|<|>|">|"<|/|\\\.\.\\).{0,9999}.* [NC,OR] 
# Block out  use of illegal or unsafe characters in the User Agent variable 
RewriteCond %{HTTP_USER_AGENT} ^.*(<|>|'|%0A|%0D|%27|%3C|%3E|%00).* [NC,OR] 
# Measures to block out  SQL injection attacks 
RewriteCond %{QUERY_STRING} ^.*(;|<|>|'|"|\)|%0A|%0D|%22|%27|%3C|%3E|%00).*(/\*|union|select|insert|cast|set|declare|drop|update|md5|benchmark).* [NC,OR] 
# Block out  reference to localhost/loopback/127.0.0.1 in the Query String 
RewriteCond %{QUERY_STRING} ^.*(localhost|loopback|127\.0\.0\.1).* [NC,OR] 
# Block out  use of illegal or unsafe characters in the Query String variable 
RewriteCond %{QUERY_STRING} ^.*(<|>|'|%0A|%0D|%27|%3C|%3E|%00).* [NC]
RewriteRule ^(.*)$ - [F]