I have a different website I tested this on. I can say that the offending problem is some place in this .htaccess file.
# BULLETPROOF .47.5 >>>>>>> SECURE .HTACCESS
# If you edit the BULLETPROOF .47.5 >>>>>>> SECURE .HTACCESS text above
# you will see error messages on the BPS Security Status page
# BPS is reading the version number in the htaccess file to validate checks
# If you would like to change what is displayed above you
# will need to edit the BPS /includes/functions.php file to match your changes
# If you update your WordPress Permalinks the code between BEGIN WordPress and
# END WordPress is replaced by WP htaccess code.
# This removes all of the BPS security code and replaces it with just the default WP htaccess code
# To restore this file use BPS Restore or activate BulletProof Mode for your Root folder again.
# BEGIN WordPress
# IMPORTANT!!! DO NOT DELETE!!! - BEGIN Wordpress above or END WordPress - text in this file
# They are reference points for WP, BPS and other plugins to write to this htaccess file.
# IMPORTANT!!! DO NOT DELETE!!! - BPSQSE BPS QUERY STRING EXPLOITS - text
# BPS needs to find the - BPSQSE - text string in this file to validate that your security filters exist
# TURN OFF YOUR SERVER SIGNATURE
ServerSignature Off
# ADD A PHP HANDLER
# If you are using a PHP Handler add your web hosts PHP Handler below
# DO NOT SHOW DIRECTORY LISTING
# If you are getting 500 Errors when activating BPS then comment out Options -Indexes
# by adding a # sign in front of it. If there is a typo anywhere in this file you will also see 500 errors.
Options -Indexes
# DIRECTORY INDEX FORCE INDEX.PHP
# Use index.php as default directory index file
# index.html will be ignored will not load.
DirectoryIndex index.php index.html /index.php
# BPS PRO ERROR LOGGING AND TRACKING - Available in BPS Pro only
# BPS Pro has premade 403 Forbidden, 400 Bad Request and 404 Not Found files that are used
# to track and log 403, 400 and 404 errors that occur on your website. When a hacker attempts to
# hack your website the hackers IP address, Host name, Request Method, Referering link, the file name or
# requested resource, the user agent of the hacker and the query string used in the hack attempt are logged.
# BPS Pro Log files are added to the P-Security All Purpose File Manager to view them.
# All BPS Pro log files are htaccess protected so that only you can view them.
# The 400.php, 403.php and 404.php files are located in /wp-content/plugins/bulletproof-security/
# The 400 and 403 Error logging files are already set up and will automatically start logging errors
# after you install BPS Pro and have activated BulletProof Mode for your Root folder.
# If you would like to log 404 errors you will need to copy the logging code in the BPS Pro 404.php file
# to your Theme's 404.php template file. Simple instructions are included in the BPS Pro 404.php file.
# You can open the BPS Pro 404.php file using the WP Plugins Editor or by using the BPS Pro File Manager.
# NOTE: By default WordPress automatically looks in your Theme's folder for a 404.php template file.
# ErrorDocument 400 /wp-content/plugins/bulletproof-security/400.php
# ErrorDocument 403 /wp-content/plugins/bulletproof-security/403.php
ErrorDocument 404 /404.php
# DENY ACCESS TO PROTECTED SERVER FILES - .htaccess, .htpasswd and all file names starting with dot
RedirectMatch 403 /\..*$
RewriteEngine On
RewriteBase /
RewriteRule ^wp-admin/includes/ - [F,L]
RewriteRule !^wp-includes/ - [S=3]
RewriteRule ^wp-includes/[^/]+\.php$ - [F,L]
RewriteRule ^wp-includes/js/tinymce/langs/.+\.php - [F,L]
RewriteRule ^wp-includes/theme-compat/ - [F,L]
RewriteEngine On
RewriteBase /
RewriteRule ^index\.php$ - [L]
# FORBID EMPTY REFFERER SPAMBOTS
RewriteCond %{REQUEST_METHOD} POST
RewriteCond %{REQUEST_URI} (wp-comments-post\.php)
RewriteCond %{HTTP_REFERER} !^.*twitterroach.com.* [OR]
RewriteCond %{HTTP_USER_AGENT} ^$
RewriteRule .* - [F]
# REQUEST METHODS FILTERED
# This filter is for blocking junk bots and spam bots from making a HEAD request, but may also block some
# HEAD request from bots that you want to allow in certains cases. This is not a security filter and is just
# a nuisance filter. This filter will not block any important bots like the google bot. If you want to allow
# all bots to make a HEAD request then remove HEAD from the Request Method filter.
# The TRACE, DELETE, TRACK and DEBUG request methods should never be allowed against your website.
RewriteEngine On
RewriteCond %{REQUEST_METHOD} ^(HEAD|TRACE|DELETE|TRACK|DEBUG) [NC]
RewriteRule ^(.*)$ - [F,L]
# PLUGINS AND VARIOUS EXPLOIT FILTER SKIP RULES
# IMPORTANT!!! If you add or remove a skip rule you must change S= to the new skip number
# Example: If RewriteRule S=5 is deleted than change S=6 to S=5, S=7 to S=6, etc.
# Adminer MySQL management tool data populate
RewriteCond %{REQUEST_URI} ^/wp-content/plugins/adminer/ [NC]
RewriteRule . - [S=12]
# Comment Spam Pack MU Plugin - CAPTCHA images not displaying
RewriteCond %{REQUEST_URI} ^/wp-content/mu-plugins/custom-anti-spam/ [NC]
RewriteRule . - [S=11]
# Peters Custom Anti-Spam display CAPTCHA Image
RewriteCond %{REQUEST_URI} ^/wp-content/plugins/peters-custom-anti-spam-image/ [NC]
RewriteRule . - [S=10]
# Status Updater plugin fb connect
RewriteCond %{REQUEST_URI} ^/wp-content/plugins/fb-status-updater/ [NC]
RewriteRule . - [S=9]
# Stream Video Player - Adding FLV Videos Blocked
RewriteCond %{REQUEST_URI} ^/wp-content/plugins/stream-video-player/ [NC]
RewriteRule . - [S=8]
# XCloner 404 or 403 error when updating settings
RewriteCond %{REQUEST_URI} ^/wp-content/plugins/xcloner-backup-and-restore/ [NC]
RewriteRule . - [S=7]
# BuddyPress Logout Redirect
RewriteCond %{QUERY_STRING} action=logout&redirect_to=http%3A%2F%2F(.*) [NC]
RewriteRule . - [S=6]
# redirect_to=
RewriteCond %{QUERY_STRING} redirect_to=(.*) [NC]
RewriteRule . - [S=5]
# Login Plugins Password Reset And Redirect 1
RewriteCond %{QUERY_STRING} action=resetpass&key=(.*) [NC]
RewriteRule . - [S=4]
# Login Plugins Password Reset And Redirect 2
RewriteCond %{QUERY_STRING} action=rp&key=(.*) [NC]
RewriteRule . - [S=3]
# TimThumb Forbid RFI By Host Name But Allow Internal Requests
RewriteCond %{QUERY_STRING} ^.*(http|https|ftp)(%3A|:)(%2F|/)(%2F|/)(w){0,3}.?(blogger|picasa|blogspot|tsunami|petapolitik|photobucket|imgur|imageshack|wordpress\.com|img\.youtube|tinypic\.com|upload\.wikimedia|kkc|start-thegame).*$ [NC,OR]
RewriteCond %{THE_REQUEST} ^.*(http|https|ftp)(%3A|:)(%2F|/)(%2F|/)(w){0,3}.?(blogger|picasa|blogspot|tsunami|petapolitik|photobucket|imgur|imageshack|wordpress\.com|img\.youtube|tinypic\.com|upload\.wikimedia|kkc|start-thegame).*$ [NC]
RewriteRule .* index.php [F,L]
RewriteCond %{REQUEST_URI} (timthumb\.php|phpthumb\.php|thumb\.php|thumbs\.php) [NC]
RewriteCond %{HTTP_REFERER} ^.*twitterroach.com.*
RewriteRule . - [S=1]
# BPSQSE BPS QUERY STRING EXPLOITS
# The libwww-perl User Agent is forbidden - Many bad bots use libwww-perl modules, but some good bots use it too.
# Good sites such as W3C use it for their W3C-LinkChecker.
# Add or remove user agents temporarily or permanently from the first User Agent filter below.
# If you want a list of bad bots / User Agents to block then scroll to the end of this file.
RewriteCond %{HTTP_USER_AGENT} (havij|libwww-perl|wget|python|nikto|curl|scan|java|winhttp|clshttp|loader) [NC,OR]
RewriteCond %{HTTP_USER_AGENT} (%0A|%0D|%27|%3C|%3E|%00) [NC,OR]
RewriteCond %{HTTP_USER_AGENT} (;|<|>|'|"|\)|\(|%0A|%0D|%22|%27|%28|%3C|%3E|%00).*(libwww-perl|wget|python|nikto|curl|scan|java|winhttp|HTTrack|clshttp|archiver|loader|email|harvest|extract|grab|miner) [NC,OR]
RewriteCond %{THE_REQUEST} \?\ HTTP/ [NC,OR]
RewriteCond %{THE_REQUEST} \/\*\ HTTP/ [NC,OR]
RewriteCond %{THE_REQUEST} etc/passwd [NC,OR]
RewriteCond %{THE_REQUEST} cgi-bin [NC,OR]
RewriteCond %{THE_REQUEST} (%0A|%0D|\\r|\\n) [NC,OR]
RewriteCond %{REQUEST_URI} owssvr\.dll [NC,OR]
RewriteCond %{HTTP_REFERER} (%0A|%0D|%27|%3C|%3E|%00) [NC,OR]
RewriteCond %{HTTP_REFERER} \.opendirviewer\. [NC,OR]
RewriteCond %{HTTP_REFERER} users\.skynet\.be.* [NC,OR]
RewriteCond %{QUERY_STRING} [a-zA-Z0-9_]=http:// [OR]
RewriteCond %{QUERY_STRING} [a-zA-Z0-9_]=(\.\.//?)+ [OR]
RewriteCond %{QUERY_STRING} [a-zA-Z0-9_]=/([a-z0-9_.]//?)+ [NC,OR]
RewriteCond %{QUERY_STRING} \=PHP[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12} [NC,OR]
RewriteCond %{QUERY_STRING} (\.\./|\.\.) [OR]
RewriteCond %{QUERY_STRING} ftp\: [NC,OR]
RewriteCond %{QUERY_STRING} http\: [NC,OR]
RewriteCond %{QUERY_STRING} https\: [NC,OR]
RewriteCond %{QUERY_STRING} \=\|w\| [NC,OR]
RewriteCond %{QUERY_STRING} ^(.*)/self/(.*)$ [NC,OR]
RewriteCond %{QUERY_STRING} ^(.*)cPath=http://(.*)$ [NC,OR]
RewriteCond %{QUERY_STRING} (\<|%3C).*script.*(\>|%3E) [NC,OR]
RewriteCond %{QUERY_STRING} (<|%3C)([^s]*s)+cript.*(>|%3E) [NC,OR]
RewriteCond %{QUERY_STRING} (\<|%3C).*embed.*(\>|%3E) [NC,OR]
RewriteCond %{QUERY_STRING} (<|%3C)([^e]*e)+mbed.*(>|%3E) [NC,OR]
RewriteCond %{QUERY_STRING} (\<|%3C).*object.*(\>|%3E) [NC,OR]
RewriteCond %{QUERY_STRING} (<|%3C)([^o]*o)+bject.*(>|%3E) [NC,OR]
RewriteCond %{QUERY_STRING} (\<|%3C).*iframe.*(\>|%3E) [NC,OR]
RewriteCond %{QUERY_STRING} (<|%3C)([^i]*i)+frame.*(>|%3E) [NC,OR]
RewriteCond %{QUERY_STRING} base64_encode.*\(.*\) [NC,OR]
RewriteCond %{QUERY_STRING} base64_(en|de)code[^(]*\([^)]*\) [NC,OR]
RewriteCond %{QUERY_STRING} GLOBALS(=|\[|\%[0-9A-Z]{0,2}) [OR]
RewriteCond %{QUERY_STRING} _REQUEST(=|\[|\%[0-9A-Z]{0,2}) [OR]
RewriteCond %{QUERY_STRING} ^.*(\[|\]|\(|\)|<|>|%3c|%3e|%5b|%5d).* [NC,OR]
RewriteCond %{QUERY_STRING} ^.*(\x00|\x04|\x08|\x0d|\x1b|\x20|\x3c|\x3e|\x5b|\x5d|\x7f).* [NC,OR]
RewriteCond %{QUERY_STRING} (NULL|OUTFILE|LOAD_FILE) [OR]
RewriteCond %{QUERY_STRING} (\./|\../|\.../)+(motd|etc|bin) [NC,OR]
RewriteCond %{QUERY_STRING} (localhost|loopback|127\.0\.0\.1) [NC,OR]
RewriteCond %{QUERY_STRING} (<|>|'|%0A|%0D|%27|%3C|%3E|%00) [NC,OR]
RewriteCond %{QUERY_STRING} concat[^\(]*\( [NC,OR]
RewriteCond %{QUERY_STRING} union([^s]*s)+elect [NC,OR]
RewriteCond %{QUERY_STRING} union([^a]*a)+ll([^s]*s)+elect [NC,OR]
RewriteCond %{QUERY_STRING} \-[sdcr].*(allow_url_include|allow_url_fopen|safe_mode|disable_functions|auto_prepend_file) [NC,OR]
RewriteCond %{QUERY_STRING} (;|<|>|'|"|\)|%0A|%0D|%22|%27|%3C|%3E|%00).*(/\*|union|select|insert|drop|delete|update|cast|create|char|convert|alter|declare|order|script|set|md5|benchmark|encode) [NC,OR]
RewriteCond %{QUERY_STRING} (sp_executesql) [NC]
RewriteRule ^(.*)$ - [F,L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /index.php [L]
# DENY BROWSER ACCESS TO THESE FILES
# wp-config.php, bb-config.php, php.ini, php5.ini, readme.html
# Replace Allow from 88.77.66.55 with your current IP address and remove the
# pound sign # from in front of the Allow from line of code below to access these
# files directly from your browser.
<FilesMatch "^(wp-config\.php|php\.ini|php5\.ini|readme\.html|bb-config\.php)">
Order allow,deny
Deny from all
#Allow from 88.77.66.55
</FilesMatch>
# IMPORTANT!!! DO NOT DELETE!!! the END WordPress text below
# END WordPress
# BLOCK HOTLINKING TO IMAGES
# To Test that your Hotlinking protection is working visit [url]http://altlab.com/htaccess_tutorial.html[/url]
#RewriteEngine On
#RewriteCond %{HTTP_REFERER} !^https?://(www\.)?add-your-domain-here\.com [NC]
#RewriteCond %{HTTP_REFERER} !^$
#RewriteRule .*\.(jpeg|jpg|gif|bmp|png)$ - [F]
# FORBID COMMENT SPAMMERS ACCESS TO YOUR wp-comments-post.php FILE
# This is a better approach to blocking Comment Spammers so that you do not
# accidentally block good traffic to your website. You can add additional
# Comment Spammer IP addresses on a case by case basis below.
# Searchable Database of known Comment Spammers [url]http://www.stopforumspam.com/[/url]
<FilesMatch "^(wp-comments-post\.php)">
Order Allow,Deny
Deny from 46.119.35.
Deny from 46.119.45.
Deny from 91.236.74.
Deny from 93.182.147.
Deny from 93.182.187.
Deny from 94.27.72.
Deny from 94.27.75.
Deny from 94.27.76.
Deny from 193.105.210.
Deny from 195.43.128.
Deny from 198.144.105.
Deny from 199.15.234.
Allow from all
</FilesMatch>
# BLOCK MORE BAD BOTS RIPPERS AND OFFLINE BROWSERS
# If you would like to block more bad bots you can get a blacklist from
# [url]http://perishablepress.com/press/2007/06/28/ultimate-htaccess-blacklist/[/url]
# You should monitor your site very closely for at least a week if you add a bad bots list
# to see if any website traffic problems or other problems occur.
# Copy and paste your bad bots user agent code list directly below.