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6G Firewall Beta

[ 6G Blacklist (beta) ] Since releasing the 5G Blacklist earlier this year, malicious server scans and bad requests have surged with more novel attacks than I’ve seen since first getting into this stuff six years ago. In other words, now is the time to beef up security and lock things down. If you’re into monitoring your server and knowing your traffic, you may be observing the same recent spike in malicious activity. In response to these attacks, I’ve been secretly working on the next generation of G-series blacklist, the inevitable 6G Firewall.

Update: Check out the new and improved 6G Firewall »

Featured in this jam-packed post:

Before getting started, take a moment to read thru the important notes, which contain information about using blacklists, server requirements, licensing, and other details. Then after presenting the 6G beta, we’ll jog through some of the thinking and strategy going into the code. Even without trying the blacklist, reading through “building the 6G Blacklist” should prove a beneficial exercise in pattern-matching and protecting against malicious HTTP behavior.

6G Blacklist beta

The 6G consists of the following sections:

  • # 6G:[USER AGENTS]
  • # 6G:[REFERRERS]
  • # 6G:[BAD IPS]

Each of these sections works independently of the others, such that you could, say, omit the entire query-string and IP-address blocks and the remaining sections would continue to work just fine. Mix-n-match to suit your needs. This code is formatted for deployment in your site’s root .htaccess file.

# @

<ifModule mod_alias.c>
 RedirectMatch 403 /(\$|\*)/?$
 RedirectMatch 403 (?i)(<|>|:|;|\'|\s)
 RedirectMatch 403 (?i)([a-zA-Z0-9]{18})
 RedirectMatch 403 (?i)(https?|ftp|php)\:/
 RedirectMatch 403 (?i)(\"|\.|\_|\&|\&amp)$
 RedirectMatch 403 (?i)(\=\\\'|\=\\%27|/\\\'/?)\.
 RedirectMatch 403 (?i)/(author\-panel|submit\-articles)/?$
 RedirectMatch 403 (?i)/(([0-9]{5})|([0-9]{6}))\-([0-9]{10})\.(gif|jpg|png)
 RedirectMatch 403 (?i)(\,|//|\)\+|/\,/|\{0\}|\(/\(|\.\.|\+\+\+|\||\\\"\\\")
 RedirectMatch 403 (?i)/uploads/([0-9]+)/([0-9]+)/(cache|cached|wp-opt|wp-supercache)\.php
 RedirectMatch 403 (?i)\.(asp|bash|cfg|cgi|dll|exe|git|hg|ini|jsp|log|mdb|out|sql|svn|swp|tar|rar|rdf|well)
 RedirectMatch 403 (?i)/(^$|1|addlink|btn_hover|contact?|dkscsearch|dompdf|easyboard|ezooms|formvars|fotter|fpw|i|imagemanager|index1|install|iprober|legacy\-comments|join|js\-scraper|mapcms|mobiquo|phpinfo|phpspy|pingserver|playing|postgres|product|register|scraper|shell|signup|single\-default|t|sqlpatch|test|textboxes.css|thumb|timthumb|topper|tz|ucp_profile|visit||webshell|wp\-lenks|wp\-links|wp\-plugin|wp\-signup|wpcima|zboard|zzr)\.php
 RedirectMatch 403 (?i)/(\=|\$\&|\_mm|administrator|auth|bytest|cachedyou|cgi\-|cvs|config\.|crossdomain\.xml|dbscripts|e107|etc/passwd|function\.array\-rand|function\.parse\-url|livecalendar|localhost|makefile|muieblackcat|release\-notes|rnd|sitecore|tapatalk|wwwroot)
 RedirectMatch 403 (?i)(\$\(this\)\.attr|\&pws\=0|\&t\=|\&title\=|\%7BshopURL\%7Dimages|\_vti\_|\(null\)|$itemURL|ask/data/ask|com\_crop|document\)\.ready\(fu|echo.*kae|eval\(|fckeditor\.htm|function.parse|function\(\)|gifamp||index.php\&amp\;quot|jfbswww|monstermmorpg|msnbot\.htm|netdefender/hui|phpMyAdmin/config|proc/self|skin/zero_vote|/spaw2?|text/javascript|this.options)

<IfModule mod_rewrite.c>
 RewriteCond %{REQUEST_URI} !^/$ [NC]
 RewriteCond %{QUERY_STRING} (mod|path|tag)= [NC,OR]
 RewriteCond %{QUERY_STRING} ([a-zA-Z0-9]{32}) [NC,OR]
 RewriteCond %{QUERY_STRING} (localhost|loopback|127\.0\.0\.1) [NC,OR]
 RewriteCond %{QUERY_STRING} (\?|\.\./|\.|\*|:|;|<|>|'|"|\)|\[|\]|=\\\'$|%0A|%0D|%22|%27|%3C|%3E|%00|%2e%2e) [NC,OR]
 RewriteCond %{QUERY_STRING} (benchmark|boot.ini|cast|declare|drop|echo.*kae|environ|etc/passwd|execute|input_file|insert|md5|mosconfig|scanner|select|set|union|update) [NC]
 RewriteRule .* - [F,L]

<ifModule mod_setenvif.c>
 #SetEnvIfNoCase User-Agent ^$ keep_out
 SetEnvIfNoCase User-Agent (<|>|'|<|%0A|%0D|%27|%3C|%3E|%00|href\s) keep_out
 SetEnvIfNoCase User-Agent (archiver|binlar|casper|checkprivacy|clshttp|cmsworldmap|comodo|curl|diavol|dotbot|email|extract|feedfinder|flicky|grab|harvest|httrack|ia_archiver|kmccrew|libwww|loader|miner|nikto|nutch|planetwork|purebot|pycurl|python|scan|skygrid|sucker|turnit|vikspider|wget|winhttp|youda|zmeu|zune) keep_out
 <limit GET POST PUT>
  Order Allow,Deny
  Allow from all
  Deny from env=keep_out

<IfModule mod_rewrite.c>
 RewriteCond %{HTTP_REFERER} (<|>|'|%0A|%0D|%27|%3C|%3E|%00) [NC,OR]
 RewriteCond %{HTTP_REFERER} ([a-zA-Z0-9]{32}) [NC]
 RewriteRule .* - [F,L]

# 6G:[BAD IPS]
 Order Allow,Deny
 Allow from all
 # uncomment/edit/repeat next line to block IPs
 # Deny from 123.456.789

Whoop, there it is, but only for testing at this point. So let me know in the comments or via email with any discoveries on 6G beta. I’ll give it at least a month or so before rolling out the official release of the 6G. This beta version is admittedly heavy-handed in some areas, so plenty of edits are expected in the process of fine-tuning and dialing it in. Your help in this process is HUGE and appreciated by myself and other 6G users.

Alright, that’s that. New beta version, but how does it work? Let’s continue with some of the thinking and strategy going into the 6G Firewall..

Behind the scenes / development strategy

Filtering URL requests with Apache involves various modules and directives:

These modules enable us to filter different parts of the request, such as the user-agent, referrer, and request-string. They operate both autonomously and cumulatively, providing much control over specific HTTP activity and server traffic in general. Apache gives us numerous ways to blacklist bad requests and block bad user agents, requests & queries to prevent hacking. To better understand how the 6G Firewall works, let’s “zoom-in” on the different modules & directives and examine some concrete examples..

Front Line: Request strings

Apache’s mod_alias module enables our frontline of defense via the RedirectMatch directive. RM is used to filter the actual base part of the URL that is requested on the server. Here are some examples of the types of nasty URL requests that are easily blocked via mod_alias/RM:

This is a great example as it shows varieties of possibly the most-scanned-for target ever: timthumb.php and its numerous incarnations. Malicious scanners also frequently target files named thumb.php and similar. Recursive scans can mean hundreds or thousands of requests hitting your server in short periods of time. This drains resources and negatively impacts site performance. As if that’s not reason enough to block such activity, if the target vulnerability is actually found on your server, it’s “game over”. So the 6G protects by blocking requests for both thumb.php and timthumb.php, using logic similar to this:

RedirectMatch 403 (?i)/(thumb|timthumb)\.php

That one line in your .htaccess file will block all URL requests that include either thumb.php and timthumb.php (not including the query string). This helps keep many malicious requests at bay, freeing up valuable resources for legit requests. Note that if you are timthumb or similar “thumb” script for your site, you will need to remove the thumb|timthumb| string from 6G (REQUEST STRINGS section).

The first “REQUEST-STRINGS” section in the 6G uses this strategy to block many different types of malicious requests. With each generation of the 6G, the various rules and patterns are further refined and updated to block the most dangerous and relevant types of requests. Pattern-matching with regular expressions enables us to block many different types of threats; however, as precise as we can get, there remain commonly scanned-for targets that are simply too common or too general to block effectively. Consider the following examples:[path]/share[path]]/login[path]/signin[path]/accepted[path]/feed.php[path]/form.php[path]/format.php[path]/plugin-editor.php[path]/post.php[path]/post-new.php[path]/wp-comments-post.php[path]/wp-conf.php[path]/wp-error.php[path]/wp-library.php[path]/wp-post.php[path]/update.php[path]/upload.php

In these examples URLs, the target string is the part appearing immediately after the “[path]/”, which is necessary to include in this post because it prevents sloppy search engines and bad bots from following these supposedly “relative” links and generating further 404 errors. But I digress.. the point here is that malicious scans frequently target existing files that are too common to block in a widely distributed firewall such as 6G. If you’re getting hit with many requests for common/well-known files, my best advice is to custom-craft a few rules based on the actual structure and content of your site.

A quick example of this, let’s say the server is getting hammered by malicious requests targeting a file named post-new.php. This file name is common enough to warrant not blacklisting in the 6G, even though it is trivial to block on an individual basis. Here at Perishable Press, I’m running WordPress in a subdirectory named “/wp/”, so I know immediately that I can safely block all requests for post.php that aren’t located in the /wp/ directory.

RewriteCond %{REQUEST_URI} !^/wp/wp-admin/post.php [NC]
RewriteCond %{REQUEST_URI} /post.php [NC]
RewriteRule .* - [F,L]

Similarly, as the post.php file is located in a subdirectory and not root, we can use mod_aliasRedirectMatch to block all requests for the file in a root-install of WordPress:

RedirectMatch 403 ^/wp-admin/post.php

With either of these methods, other common files are easily added to the rule, safely eliminating extraneous requests for non-existent files. This example serves to demonstrate one of the shortcomings of any copy/paste blacklist, while illustrating the importance of customizing and fine-tuning your own security strategy.

Filtering Query strings

Some URLs include a query-string, which is appended to the URL via question mark (?). Query strings tend to look like gibberish or random strings to the uninitiated, but are actually highly specific, well-structured data used to communicate between browser and server. Without knowing what’s happening on your server, it may difficult to discern between good and bad query-string requests, but there are some things to look for:

  • Unusual and/or unexpected characters such as additional question marks, angled brackets, asterix, and so on
  • Unencoded characters that should be encoded, such as these: $ & + , / : ; = ? @
  • Super-long random-looking strings of encoded gibberish, alphanumeric or laced with symbols such as %
  • Super-short query strings that may seem to terminate abruptly, often with a single quote ('), double quote ("), or equal sign (=)

There are other signs as well, but ultimately it comes down to whether the request is understood or not by the server. If it’s not, the request could be a simple 404 error or similar, or it could be malicious. Generally the one-off 404s are the result of typos or other human errors, and tend to appear sporadically or infrequently in the server-access logs. Contrast this with malicious query-string requests that occur frequently, in rapid succession, targeting non-existent files with encoded gibberish and other nonsense.

With the 5G Blacklist in place, many evil query-string requests are blocked, but with the recent surge of scanning activity, a new breed of encoded nasty was getting through, looking similar to these examples:


As you can see, these malicious strings contain numerous common-denominators that could be matched against, such as:

  • %2C matching the UTF-8 (hex) encoded encoded comma (,) would be partially effective
  • == matching two equal signs would be partially effective
  • Other character combinations..?

We could match the hex-encoded comma, but that’s such a common character that it would cause more problems than it would solve (in most cases), so really not an option. Looking closely at other possible character-combinations, suddenly the “least-common denominator” hits you: long, random sequences of alphanumeric characters appear in all of these examples, and many others that I’ve encountered. Thus, in the query-string section of the 6G, excessively long strings of alphanumeric characters are effectively blocked with the following rule:

RewriteCond %{QUERY_STRING} ([a-zA-Z0-9]{32}) [NC,OR]

Yeah.. the trick here is choosing the optimal number of sequential characters to match against. If we set the match to, say, {16}, the number of false positives increases; conversely, if we set the match to a larger number, such as {64}, the number of false negatives increases. So once again it’s all about finding the balance.

Important note about placement of the 6G query-string rules within the .htaccess file. If the query-string rules don’t seem to be working, try moving them to appear before any other mod_rewrite rules that may be in play. I’m not sure why this is the case, but I think it has something to do with the query-string data being unavailable for processing after the first encounter with mod_rewrite. Any info on this would be appreciated :)

Blocking Bad User-agents

The next two sections in the 6G protect against some of the worst user-agents and referrers from messing with your site. The technique is essentially the same as with the request-string and query-string sections, but filters different properties of the URI request.

The specified user-agent of a request may consist of multiple elements, and it may be empty. Previous versions of the g-series blacklist block empty (or “blank”) user-agents with the following rule:

SetEnvIfNoCase User-Agent ^$ keep_out

This rule “flags” any request from a blank user-agent, and worked well for many years. These days, however, social-media, mobile apps, PayPal, and certain Ajax requests frequently use an empty string as the user-agent when interacting with the server. For example, Google requires the blank user-agent in order to display thumbnails for Google+. So at this point the pros/cons of blocking bad empty requests is a no-brainer and the rule is now “deprecated” (commented-out) with a pound-sign (#).

Beyond this, the 6G USER-AGENTS section includes new rules to block malicious character-strings operating via the user-agent string. The 5G blocks some of the “worst of the worst” known bad user-agents, stuff like:

  • binlar
  • nutch
  • sucker
  • zmeu

Plus around 20 other nasty agents are blocked in the 5G, with the entire “USER-AGENT” section included as sort of a template for individual customization. Unfortunately, there are increasing numbers of malicious strings being passed as the user-agent, so the 6G includes more protection in this area. The 6G not only blocks additional well-known bad agents, it protects against encoded strings, forbidden characters, and other malicious garbage. Most of this is accomplished with a single new directive:

SetEnvIfNoCase User-Agent (<|>|'|<|%0A|%0D|%27|%3C|%3E|%00|href\s) keep_out

These character strings have no business appearing in the user-agent string. Most if not all of the widely used browsers such as Firefox, Chrome, Opera, IE, mobile browsers, feed readers, and even borderline/questionable scripts and bots refrain from suing any of these forbidden characters in their user-agent description. For example, here is Chrome’s reported user-agent:

Mozilla/5.0 Macintosh Intel Mac OS X 10_6_8 AppleWebKit/536.5 KHTML, like Gecko Chrome/19.0.1084.46 Safari/536.5

Legitimate user-agents contain only valid strings, so blocking illegal characters is an effective way to filter directory-traversals, XSS attacks, and other malicious exploits.

Blocking Bad Referrers

The 6G Firewall/Blacklist also includes new directives for blocking bad referrers. The strategy here is similar to that of the additional QUERY-STRING rules: filtering malicious character-strings to protect against bad referrers. Referrer information isn’t always included with the request, so we don’t want to block blank referrers, but forbidden characters are safely blocked, as are long strings (32 characters or more) of strictly alphanumeric characters. A simple and effective strategy using the following two filters:

RewriteCond %{HTTP_REFERER} (<|>|'|%0A|%0D|%27|%3C|%3E|%00) [NC,OR]
RewriteCond %{HTTP_REFERER} ([a-zA-Z0-9]{32}) [NC]

This also serves as a template for further customization. If you’re seeing lots of weird referrers filling your access/error logs, the REFERRERS section of the 6G will help to curb the riff-raff.

Blocking Bad IPs

Blocking by IP address is best used for specific threats, either individual, or by region, country, or similar. With a strong firewall, blocking IPs is unnecessary unless someone or something is attacking you specifically with requests that aren’t being blocked. I’ve heard from a number of people saying that their sites are being targeted/harassed by weird stalkers, enemies, spurned lovers, and it goes on and on. I’ve experienced this through a chat/forum site that had attracted all sorts of low-life, bottom-feeding douche-bags. They would just jump into the chat at random and ruin the conversation with potty humor and juvenile slurs. The PHP blacklist for the chat script wasn’t catching a lot of the garbage, so it was a perfect time to check the logs and ban the fools individually. After a bit of research and a few lines of .htaccess, the idiots were gone and peace was restored to the chat forum.

Thus, for the purpose of blocking individual threats the “bad-IPs” section of the 6G is entirely optional and intended as a template to use should the need arise. By default, the bad-IPs section in the 6G is empty, but over the past few months I’ve assembled my own private collection of blacklisted IP addresses. These are the some of the worst offenders I’ve seen this year:

# 2012 IP Blacklist
 Deny from
 Deny from
 Deny from
 Deny from
 Deny from
 Deny from
 Deny from
 Deny from
 Deny from
 Deny from
 Deny from
 Deny from
 Deny from
 Deny from
 Deny from
 Deny from
 Deny from
 Deny from
 Deny from
 Deny from
 Deny from

Including these IPs is entirely optional — they are provided here mostly for reference, but also for über-paranoid faction ;)

Further reading..

For more information on blacklisting, regular-expressions, and .htaccess methods, here are some choice offerings from the archives:

And of course, many more articles in the Perishable Press Archives.

Thanks to..

Thank you to everyone who contributes to the g-series blacklist with feedback, suggestions, test-results, and links. Specifically for the 6G beta, huge thanks goes to Ken Dawes and Andy Wrigley for their generous help.

Important notes..

This is the beta release of the 6G Blacklist. There have been many improvements, including optimized code, greater accuracy, and better overall protection. I’ve been running the 6G (in its various incarnation) here at Perishable Press for the past several weeks and have been well-pleased with the results. The 6G is pretty slick stuff, but there are some important things to keep in mind:

It takes more than a blacklist to secure your site
No one single security measure is perfect; good security is the result of many concerted strategic layers of protection. The 6G is designed to better secure your site by adding a strong layer of protection.
Sometimes blacklists block legit requests
A perfect firewall would block only bad traffic, but in reality it’s inevitable that some good requests get blocked. The goal is to keep the number of false positives to a minimum while maximizing the effectiveness of the ruleset. It’s a statistical game of sorts.
Resolving issues..
If/when you do encounter a potential false positive (e.g., you can’t load a certain page), there is a simple way to determine if it’s that crazy chunk of blacklist code you stuck into your .htaccess file. If you remove the blacklist and the page in question begins to work, well, you’ve can either forget about it or take a few moments to locate the offending rule and remove it from the list. I’ve found that it’s better to “comment out” rather than delete as it’s easier to keep track of things when the inevitable next version of the blacklist hits the streets.
This is beta.
And most importantly, this is the beta version of the 6G. As mentioned, there’s a lot of new stuff happening with this blacklist, and it’s super-important for me to thoroughly test via widest base possible. Only use this code if you are savvy and want to help out by reporting data, errors, logs, or whatever. That said, this “beta” version has been running flawlessly on multiple sites, including one that’s super-complex with many themes, plugins, and customizations (i.e., this site).
It’s all you.
Once the code leaves this site, you assume all responsibility. Always back up your original working .htaccess file and you should be good to go.
Server requirements
Linux/Apache or similar (if adapted). 6G is formatted for deployment in .htaccess files, and also works when formatted for use directly in the Apache main configuration file. For the required Apache modules, see this list.
GNU General Public License.

I freely share my work on the g-series blacklist to help the community better protect their sites against malicious activity. If you find it useful, please show support by linking and sharing so others may learn and benefit as well. Thanks.

About the Author
Jeff Starr = Creative thinker. Passionate about free and open Web.
GA Pro: Add Google Analytics to WordPress like a pro.

185 responses to “6G Firewall Beta”

  1. WordPress site
    Thank you very much for your great work !
    Hello , total new head here , but its fascinating to see how these magic code works ! Tried 6G and just little problem , on QUERY STRINGS when I delete REWRITE RULE F,L IT WORKS ! no any internal errors. I Checked with and pretty much it works . Could any one help me get a pointer or tips Plus Could any one help me understand what does this mean in a simple form –
    Note that if you are timthumb or similar “thumb” script for your site, you will need to remove the thumb|timthumb| string from 6G (REQUEST STRINGS section).
    will greatly appreciate your help ….Thank you !

  2. T. J. Brumfield 2012/06/21 1:50 pm

    I have a few plugins where I’m getting 403 errors trying to access paths with “inc” in them. I’m not sure why.

    • Do these paths have long file names? I had a possibly similar problem with images being 403’d. They were blocked, was not because of “jpg” in the url, but because of the “character count” in “RedirectMatch 403 (?i)([a-zA-Z0-9]{18})” which I upped from 18 to 50 to solve the problem.

      It may be worth trying this for your “inc” problem.

      • T. J. Brumfield 2012/06/24 9:03 am

        I found the issue. It was not the fact that these paths both have inc in them, but both paths had two slashes in a row. The WordPress plugin took one path variable ending in a slash and added it to another with one beginning with a slash. So the url was something like:


        I edited the plugin to remove one of those slashes. However, I’m curious if any of these rules would cause a 403 for that reason.

      • T. J. Brumfield 2012/06/28 6:18 am

        I just got bit by the same thing. Another WordPress plugin had two slashes in a row in a path, except this was a caching plugin so any cached content came back with a 403 and it effectively broke my entire site.

        Which rule(s) is blocking two slashes?

      • The line beginning with these characters:

        RedirectMatch 403 (?i)(\,|//|\)

        ..blocks two slashes in the second pattern in. I’ve seen the w3 total-cache plugin generate URLs with double slashes. It’s okay to remove that string from the list, but fixing the plugin would be an actual solution.

  3. Hi,

    Trying to help with some feedback:

    I’ve been testing this new version on some sites, and there’s a chunk of code that makes the css coming from the admin (not the front-end) to not load:


    Editor’s note: removed the 6G block of code (redundant)

    So on the wp-admin, there’s no styling at all, and on the front-end, the theme loads ok, but the admin bar appears with no styles. If you’d like any more info about this I’ll be happy to provide it.

    Thanks for sharing this valuable resource!

    • Bobby Jones (previous page of comments) reported a similar problem with CSS. He solved it by changing the {32} in line 3 of the Query Strings section to {150} . This may solve your problem. HTH

      • Hi, thanks for the tip! I tried it but it didn’t work. I went on commenting one line at a time, and the line that’s causing this effect is actually below that one:

        RewriteCond %{QUERY_STRING} (?|../|.|*|:|;|<|>|'|"|)|[|]|=\'$|%0A|%0D|%22|%27|%3C|%3E|%00|%2e%2e) [NC,OR]

        If I get to solve it I’ll post another comment, otherwise you’re free to look.

        Huge thanks!!

    • Jeff Starr 2012/06/26 7:01 pm

      Thanks for the feedback, aleSub. I’ll be sure to resolve this issue for the final version of 6G :)

  4. Peter Mumford 2012/06/24 12:41 pm

    is it possible to load the blacklist with @import? It would make maintaining multiple sites simpler. I could just change one file, all my sites would import that.

    I have a lot of sites to maintain. Its hard to keep up with the security of all of them.

    • Jeff Starr 2012/06/26 7:04 pm

      Hi Peter, I’m not sure about loading with @import for .htaccess directives, but if you have access to Apache’s main configuration file, httpd.conf, placing the list there would enable you to protect any/all sites on the server.

  5. Tam Nguyen 2012/06/25 4:47 pm

    Hey Jeff, I think I’m noticing a slight performance hit after I added the block. Do you have any firm idea that that might be the cause? I’ve since commented out the following code (I’d added a few IPs that I collect as well):

    # 5G:[BAD IPS]
    # Order Allow,Deny
    # Allow from all
    # Deny from,,,,,,,,,,,,,,,,,,,,,,,,,

    • T. J. Brumfield 2012/06/25 5:04 pm

      Looking through my access logs, I have hackers in Romania, Thailand, Taiwan and China all trying to do SQL injection, access PHPMyAdmin and more. I’ve decided to block the entire countries by IP, which got me thinking.

      It is far better blocking IP addresses at the firewall level, than at the .htaccess level. .htaccess is parsed with every page load.

      I also moved all these rules in an Apache site conf, and turned off Overrides, so I don’t parse .htaccess with each page load to also help with performance.

      I’m not very good with regex or rewrite rules. I’d like to consolidate the rules I have. Two different WordPress security plugins wrote some similiar rules that also overlap with these. Is there someone who would be willing to look over my rewrite rules to consolidate them?


      • Tam Nguyen 2012/06/25 5:06 pm

        Unfortunately, I run a blog on a shared host on Dreamhost, so I don’t have access to the actual machine :(

    • Jeff Starr 2012/06/26 7:09 pm

      Hi Tam, as explained by T. J., it would be better for performance to add the 6G rules directly to the main configuration file (httpd.conf). As it looks like that’s not possible, I would remove the 5G:[BAD IPS] section from the blacklist as you have done. Hopefully that helps with any performance issues.

  6. Tam Nguyen 2012/06/25 4:50 pm

    I should add that ever since I added the blacklisted IP list block, I noticed in my access logs that all client’s IPs are reverse DNS looked up, which takes more time, and that’s why I drew the conclusion. Also, I have W3TC that I integrate Amazon Cloudfront, and I get the sporadic 504 Gateway timeout error.

    • Jeff Starr 2012/06/26 7:11 pm

      Yes, definitely remove the IP section from 6G.. as discussed in the article, it’s not essential and the remainder of the blacklist will continue to work fine.

  7. Hi there after adding this to my my apache htaccess file.

    I cant acces piwik stats properly. When i remove 6g Piwik is working fine.
    What do i need to remove or change to get it working?

    • Basically you just need to do a little testing to locate the cause of the issue.. remember this is a beta version of the 6G, so if any doubt, please refrain from using.

    • Glenn Dixon 2012/11/15 7:57 am

      Astral – I resolved this by editing line 3 of the query strings section – change {32} to {64}

  8. Peter Mumford 2012/07/02 11:14 am

    Jeff, are you working with the WP security team at all?

  9. Yael K. Miller 2012/07/03 10:06 am

    General question about blocking bad IPs: The security plugins I’m using are doing a good job of blocking IPs that are trying to access my website by forcing a login (or whatever it’s called). When I started using the plugin, every time I got a message that an IP was temporarily blocked I would immediately add it to IP blacklist. But this takes time as I have a lot of websites.

    You mention that blocking IP addresses is optimal for individuals who are being douche-bags. And as for hackers, looking at my logs, it’s clear if you block one IP address hackers just use another one.

    In your opinion, whenever I get a notification that my security plugin temporarily blocked an IP address because they were trying to login, should I put that IP address in my ever-expanding IP blacklist?

    • Great question and definitely “no” you should not worry too much about maintaining any type of IP blacklist. They’re really only practical for stopping specific threats and attacks. If you’re blocking the automated scripts trying to get in, that should be more than enough, no need to keep a diary in your .htaccess file.

  10. I had an issue using this with my website. Certain images would not appear after adding the 6G code. When I switched to the 5G, things went back to normal with good performance. Any idea what went wrong?

    • Jeff Starr 2012/07/05 6:35 pm

      Difficult to guess without a closer look.. but no worries cuz this is just the beta version. For now I recommend 5G :)

  11. I am wondering if I am the only encountering this issue, whenever I add the whole # 6G:[REQUEST STRINGS] block it destroys my theme.

  12. And when I put the block # 6G:[REQUEST STRINGS] I couldn’t edit themes, deactivate/activate my plugins.

    • Thanks for the input, Arsie! Honestly though this is a BETA version, so only use if you’re familiar with troubleshooting .htaccess. Otherwise, go with the 5G until 6G is ready. Thanks!

      • Thanks Jeff, just a question though. I am new to optimizing .htaccess, with “RedirectMatch 403” will it still work if I don’t have the physical 403 page?

      • Yes, Apache generates all error-pages by default (and also makes them easy to customize).

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Perishable Press is operated by Jeff Starr, a professional web developer and book author with two decades of experience. Here you will find posts about web development, WordPress, security, and more »
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