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The Perishable Press 4G Blacklist

[ 4G Stormtrooper ] At last! After many months of collecting data, crafting directives, and testing results, I am thrilled to announce the release of the 4G Blacklist! The 4G Blacklist is a next-generation protective firewall that secures your site against a wide range of automated attacks and other malicious activity.

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

Like its 3G predecessor, the 4G Blacklist is designed for use on Apache servers and is easily implemented via HTAccess or the httpd.conf configuration file. In order to function properly, the 4G Blacklist requires two specific Apache modules, mod_rewrite and mod_alias. As with the third generation of the blacklist, the 4G Blacklist consists of multiple parts:

  • HTAccess Essentials
  • Request-Method Filtering
  • IP Address Blacklist
  • Query-String Blacklist
  • URL Blacklist

Each of these methods is designed to protect different aspects of your site. They may be used independently, mixed and matched, or combined to create the complete 4G Blacklist. This modularity provides flexibility for different implementations while facilitating the testing and updating process. The core of the 4G Blacklist consists of the last two methods, the Query-String and URL Blacklists. These two sections provide an enormous amount of protection against many potentially devastating attacks. Everything else is just icing on the cake. Speaking of which, there are also two more completely optional sections of the 4G Blacklist, namely:

These two sections have been removed from the 4G Blacklist and relegated to “optional” status because they are no longer necessary. Put simply, the 4G Blacklist provides better protection with fewer lines of code. Even so, each of these blacklists have been updated with hundreds of new directives and will be made available here at Perishable Press in the near future. But for now, let’s return to the business at hand..

Presenting the Perishable Press 4G Blacklist

As is custom here at Perishable Press, I present the complete code first, and then walk through the usage instructions and code explanations. So, without furhter ado, here is the much-anticipated 4G Blacklist [for personal use only – may not be posted elsewhere without proper link attribution]:

### PERISHABLE PRESS 4G BLACKLIST ###

# ESSENTIALS
RewriteEngine on
ServerSignature Off
Options All -Indexes
Options +FollowSymLinks

# FILTER REQUEST METHODS
<IfModule mod_rewrite.c>
 RewriteCond %{REQUEST_METHOD} ^(TRACE|DELETE|TRACK) [NC]
 RewriteRule ^(.*)$ - [F,L]
</IfModule>

# BLACKLIST CANDIDATES
<Limit GET POST PUT>
 Order Allow,Deny
 Allow from all
 Deny from 75.126.85.215   "# blacklist candidate 2008-01-02 = admin-ajax.php attack "
 Deny from 128.111.48.138  "# blacklist candidate 2008-02-10 = cryptic character strings "
 Deny from 87.248.163.54   "# blacklist candidate 2008-03-09 = block administrative attacks "
 Deny from 84.122.143.99   "# blacklist candidate 2008-04-27 = block clam store loser "
 Deny from 210.210.119.145 "# blacklist candidate 2008-05-31 = block _vpi.xml attacks "
 Deny from 66.74.199.125   "# blacklist candidate 2008-10-19 = block mindless spider running "
 Deny from 203.55.231.100  "# 1048 attacks in 60 minutes"
 Deny from 24.19.202.10    "# 1629 attacks in 90 minutes"
</Limit>

# QUERY STRING EXPLOITS
<IfModule mod_rewrite.c>
 RewriteCond %{QUERY_STRING} \.\.\/    [NC,OR]
 RewriteCond %{QUERY_STRING} boot\.ini [NC,OR]
 RewriteCond %{QUERY_STRING} tag\=     [NC,OR]
 RewriteCond %{QUERY_STRING} ftp\:     [NC,OR]
 RewriteCond %{QUERY_STRING} http\:    [NC,OR]
 RewriteCond %{QUERY_STRING} https\:   [NC,OR]
 RewriteCond %{QUERY_STRING} mosConfig [NC,OR]
 RewriteCond %{QUERY_STRING} ^.*(\[|\]|\(|\)|<|>|'|"|;|\?|\*).* [NC,OR]
 RewriteCond %{QUERY_STRING} ^.*(%22|%27|%3C|%3E|%5C|%7B|%7C).* [NC,OR]
 RewriteCond %{QUERY_STRING} ^.*(%0|%A|%B|%C|%D|%E|%F|127\.0).* [NC,OR]
 RewriteCond %{QUERY_STRING} ^.*(globals|encode|config|localhost|loopback).* [NC,OR]
 RewriteCond %{QUERY_STRING} ^.*(request|select|insert|union|declare|drop).* [NC]
 RewriteRule ^(.*)$ - [F,L]
</IfModule>

# CHARACTER STRINGS
<IfModule mod_alias.c>
 # BASIC CHARACTERS
 RedirectMatch 403 \,
 RedirectMatch 403 \:
 RedirectMatch 403 \;
 RedirectMatch 403 \=
 RedirectMatch 403 \@
 RedirectMatch 403 \[
 RedirectMatch 403 \]
 RedirectMatch 403 \^
 RedirectMatch 403 \`
 RedirectMatch 403 \{
 RedirectMatch 403 \}
 RedirectMatch 403 \~
 RedirectMatch 403 \"
 RedirectMatch 403 \$
 RedirectMatch 403 \<
 RedirectMatch 403 \>
 RedirectMatch 403 \|
 RedirectMatch 403 \.\.
 RedirectMatch 403 \/\/
 RedirectMatch 403 \%0
 RedirectMatch 403 \%A
 RedirectMatch 403 \%B
 RedirectMatch 403 \%C
 RedirectMatch 403 \%D
 RedirectMatch 403 \%E
 RedirectMatch 403 \%F
 RedirectMatch 403 \%22
 RedirectMatch 403 \%27
 RedirectMatch 403 \%28
 RedirectMatch 403 \%29
 RedirectMatch 403 \%3C
 RedirectMatch 403 \%3E
 RedirectMatch 403 \%3F
 RedirectMatch 403 \%5B
 RedirectMatch 403 \%5C
 RedirectMatch 403 \%5D
 RedirectMatch 403 \%7B
 RedirectMatch 403 \%7C
 RedirectMatch 403 \%7D
 # COMMON PATTERNS
 Redirectmatch 403 \_vpi
 RedirectMatch 403 \.inc
 Redirectmatch 403 xAou6
 Redirectmatch 403 db\_name
 Redirectmatch 403 select\(
 Redirectmatch 403 convert\(
 Redirectmatch 403 \/query\/
 RedirectMatch 403 ImpEvData
 Redirectmatch 403 \.XMLHTTP
 Redirectmatch 403 proxydeny
 RedirectMatch 403 function\.
 Redirectmatch 403 remoteFile
 Redirectmatch 403 servername
 Redirectmatch 403 \&rptmode\=
 Redirectmatch 403 sys\_cpanel
 RedirectMatch 403 db\_connect
 RedirectMatch 403 doeditconfig
 RedirectMatch 403 check\_proxy
 Redirectmatch 403 system\_user
 Redirectmatch 403 \/\(null\)\/
 Redirectmatch 403 clientrequest
 Redirectmatch 403 option\_value
 RedirectMatch 403 ref\.outcontrol
 # SPECIFIC EXPLOITS
 RedirectMatch 403 errors\.
 RedirectMatch 403 config\.
 RedirectMatch 403 include\.
 RedirectMatch 403 display\.
 RedirectMatch 403 register\.
 Redirectmatch 403 password\.
 RedirectMatch 403 maincore\.
 RedirectMatch 403 authorize\.
 Redirectmatch 403 macromates\.
 RedirectMatch 403 head\_auth\.
 RedirectMatch 403 submit\_links\.
 RedirectMatch 403 change\_action\.
 Redirectmatch 403 com\_facileforms\/
 RedirectMatch 403 admin\_db\_utilities\.
 RedirectMatch 403 admin\.webring\.docs\.
 Redirectmatch 403 Table\/Latest\/index\.
</IfModule>

That’s the juice right there. This 4G Blacklist is some powerful stuff, blocking and filtering a wide range of potential attacks and eliminating tons of malicious nonsense. Much care has been taken to beta test this firewall on multiple configurations running various types of software, however, due to my limited financial resources, it is impossible to test the 4G as comprehensively as I would have preferred. Even so, for the average site running typical software, everything should continue to work perfectly. With that in mind, please read through the remainder of the article before implementing the 4G Blacklist.

Installation and Usage

Before implementing the 4G Blacklist, ensure that you are equipped with the following system requirements:

  • Linux server running Apache
  • Enabled Apache module: mod_alias
  • Enabled Apache module: mod_rewrite
  • Ability to edit your site”s root htaccess file (or)
  • Ability to modify Apache’s server configuration file

With these requirements met, copy and paste the entire 4G Blacklist into either the root HTAccess file or the server configuration file ( httpd.conf ). After uploading, visit your site and check proper loading of as many different types of pages as possible. For example, if you are running a blogging platform (such as WordPress), test different page views (single, archive, category, home, etc.), log into and surf the admin pages (plugins, themes, options, posts, etc.), and also check peripheral elements such as individual images, available downloads, and alternate protocols (FTP, HTTPS, etc.).

While the 4G Blacklist is designed to target only the bad guys, the regular expressions used in the list may interfere with legitimate URL or file access. If the directives in the blacklist are blocking a specific URL, the browsing device will display a 403 Forbidden error; similarily, if the blacklist happens to block a file or resource required for some script to function properly, the script (JavaScript, PHP, etc.) may simply stop working. If you experience either of these scenarios after installing the blacklist, don’t panic! Simply check the blocked URL or file, locate the matching blacklist string, and disable the directive by placing a pound sign ( # ) at the beginning of the associated line. Once the correct line is commented out, the blocked URL should load normally. Also, if you do happen to experience any conflicts involving the 4G Blacklist, please leave a comment or contact me directly.

Set for Stun

As my readers know, I am serious about site security. Nothing gets my juices flowing like the thought of chopping up mindless cracker whores into small, square chunks and feeding their still-twitching flesh to a pack of starving mongrels. That’s good times, but unfortunately there are probably laws against stuff like that. So in the meantime, we take steps to secure our sites using the most effective tools at our disposal. There is no one single magic bullet that will keep the unscrupulous bastards from exploiting and damaging your site, but there are many cumulative steps that may be taken to form a solid security strategy. Within this cumulative context, the 4G Blacklist recognizes and immunizes against a broad array of common attack elements, thereby maximizing resources while providing solid defense against malicious attacks.

Many Thanks

A huge “Thank You” to the dedicated people who helped beta test the 4G Blacklist. Your excellent feedback played an instrumental role in the development of this version. Thank you!

Further Reading

For more insight into the mysterious realms of blacklisting, the creation of the Perishable Press Blacklist, and DIY site security in general, check out some of my other articles:

Next Up

Next up in the March 2009 Blacklist Series: The Ultimate User-Agent Blacklist. Don’t miss it!

Updates

Since the release of the 4G Blacklist, several users have discovered issues with the following 4G directives.

Joomla

In the query-string section, Joomla users should delete the following patterns:

request
config
[
]

In the character-string section, Joomla users should comment-out or delete the following lines:

RedirectMatch 403 \,
RedirectMatch 403 \;
RedirectMatch 403 config\.
RedirectMatch 403 register\.

WordPress

In the query-string section of the 4G Blacklist, the following changes have been made:

"%3D" character-string has been changed to "%5C"

Likewise, in the character-string section, the following change has been made:

"wp\_" character-string has been removed

And in the request-method filtering section, the following change has been made:

"HEAD" method has been removed

Also, the following changes may be necessary according to which plugins you have installed:

Ozh' Admin Drop Down Menu - remove "drop" from the query-string rules
WordPress' Akismet - remove "config" from the query-string rules

OpenID

OpenID users should read the information in this comment.

SMF

SMF users should read the information in this comment.

vBulletin

vBulletin users should read the information in these comments.

Jeff Starr
About the Author Jeff Starr = Fullstack Developer. Book Author. Teacher. Human Being.
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233 responses
  1. Oh, How to apply 4G to SMF 2.0 RC3.

    Advise or tips appreciated. Have a fresh install of this. “Will test for Tips”

  2. Thanks so much for this one. Hope this will decrease the times my site gets hacked.

    Two thumbs up

  3. Jacky Liang September 8, 2010 @ 2:23 pm

    Returns a 403 Error with WPTouch Mobile Theme.

  4. I didn’t set out to block download managers, but I am now after someone using FDM (Free Download Manager) knocked one of my sites over its traffic allowance with over 50,000 requests for a 6 Mb file. (that’s just the first 50,000 lines of an 80 Mb access log!). Each 206 code was showing just 3 Kb as the chunk size. Had the same affect as a DDOS attack.

    I added ^fdm to the user-agents (wasn’t cloaked) and will keep an eye on the logs. Any other advice on preventing this would be much appreciated.

  5. Hi, thanks for great list.

    I use SEF urls and I got the forbidden page when I open

    www.mysite.com/Thread-anubis-poetry--1059

    Could you please tell me what should I remove?

    Thank you in advance!

  6. sorry , the right link is

    http://www.mysite.com/Thread-anubis-poetry- - 1059

    (double dash in fornt of number of post)

  7. 2 things. I found this site and it shows hackers trying to use php scipts and other stuff in the user agent. Is this something that should be added to 4g or is it not required. see the first article.

    http://www.botsvsbrowsers.com/

    @ Jeff Starr
    I have been making my htaccess file for about 6 months, i have included most of the stuff of your website (stuff from other sites aswell) and made it into an easy to follow file. The idea is when i am happy with it to release it to the public. Maybe throught this site. Did you want to look at it. It has the following sections. gloabl/security/perfomance/usability. I also rigged it so when any of the section rules get activated i get an email with all the details (very handy for finding out what rules stops what joomla plugin from working).

    shoulders

  8. Jeff Starr

    @shoulders: I would be happy to look at it and release here if everything looks good. If interested send via email to Jeff at this domain. Thanks!

  9. @shoulders, I would be interested in your joomla version.
    i’ve found a few issues with Jeffs list and using a joomla site. had to edit it quite harshly to stop db server errors.

  10. Hello Jeff. First of all, thank you very much for sharing such an useful piece of code. I’ve been using a very light version of this (customized from different pieces found in the Internet) for a while and I’ve seen a very significant drop in bandwith usage, so I’m all sold for this kind of technique to keep (at least some) of the bad guys away. Anyway, I found your code and I’m trying to use it in some of my sites (just testing for now) but one of the first things I noticed is that neither this nor your 2010 UA blacklist seems to catch blank (empty) user-agents, which in my very own case were among the biggest bandwidth hogs. Is there any reason for it? What would be the best way to add a rule for that? I just appended RewriteCond %{HTTP_USER_AGENT} ^$ [NC] just before RewriteRule ^(.*)$ – [F,L] and it seems to be working OK. Thanks in advance for your response!

  11. Jeff Starr

    Proteo, yes that would work fine, but be careful blocking empty user-agents: some of them are legitimate requests. This is why I have yet to include a similar block in the 4G/5G Blacklist. Still working on the 5G though, so it may end up in there.

  12. First, thank you. I just found your site for the first time and have been doing a lot of reading.

    I have a question in regards to the regular expressions you use.

    Is there a reason you use ^.* at the beginning and .* at the end of the following line?
    RewriteCond %{QUERY_STRING} ^.*(\[|\]|\(|\)||'|"|;|\?|\*).* [NC,OR]

    Isn’t this effectively the same?
    RewriteCond %{QUERY_STRING} (\[|\]|\(|\)||'|"|;|\?|\*) [NC,OR]

    Also, is there a reason you can’t use a character class for the above? I find the following easier to read.
    RewriteCond %{QUERY_STRING} [[\]()'";?*] [OR]

    I was always taught not to use groupings if it can be avoided. Same goes for the following.
    RewriteRule ^(.*)$ - [F,L]

    There is no need for the group unless you are going to use a back reference. So I would think this is better.
    RewriteRule .* - [F,L]

    I was also wondering about blocking the backslash. I see you have blocked %5c, but I don’t see where you have blocked the literal backslash. Is there a reason for this?

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