Joomla! websites abused as open proxy for Denial-of-Service attacks

Joomla websites using the Googlemaps plugin for Joomla are actively abused as open proxy for launching Denial-of-Service (DoS) attacks. Even though the Googlemaps plugin vulnerability plugin_googlemap2_proxy.php was released over one and a half (1,5) years ago, I still see these DoS-attacks happening on a regular basis…

Joomla security

Security in Joomla has a bad track record… This isn’t the first vulnerability in a Joomla! plugin or component (and won’t be the last). We all remember the Joomla Content Editor (JCE) and Media Manager vulnerabilities and exploits.

It seems Joomla! website owners tend to not update their sites, which is very bad of course.

Joomla! Googlemaps plugin vulnerability

The problem with the Joomla! Googlemaps plugin lies in the fact anyone can request the /plugins/system/plugin_googlemap2_proxy.php in their browser or script, to execute cURL HTTP requests to remote websites. The url parameter is vulnerable for Cross Site Scripting (XSS) attacks, and allows the retrieval of remote website content.

When this happens a lot, a website becomes overloaded and unresponsive, making a Denial-of-Service attack successfully executed.

This is not only a problem for the website owner on the remote end, or its hosting company. Your web servers transmit a lot of HTTP traffic to remote ends, increasing server load, usage and network bandwidth (for which you pay). Therefor it’s important to stop this abuse.

An example request I pulled from a website logfile:

2014-11-16 08:54:25 1.1.1.1 GET /plugins/system/plugin_googlemap2_proxy.php
  url=www.victim_site.example 80 -
  193.23.181.130 Mozilla/5.0+(Windows+NT+6.1;+WOW64)+AppleWebKit/537.36+
    (KHTML,+like+Gecko)+Chrome/37.0.2062.124+Safari/537.36 - 
  example.com 200 0 64 0 252 42558

Pro tip: learn about the Top Ten Joomla Security Problems… and how to avoid them. Tip #2, learn to optimize Joomla!!

Mitigate Joomla! Googlemaps plugin proxy Denial-of-Service attacks

A quick search on one web server for the file plugin_googlemap2_proxy.php showed me it’s used a lot. Those Joomla! sites are running older 1.5.x versions too sigh… So, let’s stop these DoS attacks on remote sites.

Interesting:   Be careful with cheap Chinese Android smartphones - Uupay.D trojan pre-installed

Update & Tune Joomla! security & performance
It’s important to update Joomla!, to improve it’s security and performance. See the Speed up Joomla! for more information.

Project Honeypot – Mitigate DDoS & web attacks
A mitigation is to implement a Project Honeypot solution to filter and block IP addresses on the HTTP level. They call their HTTP blacklist Http:BL. Join and work with Project Honeypot to add IP addresses of abusers to their database, create new, or improve existing implementations for Http:BL, or donate a small amount of money to the cause. Of course you can create your own HTTP blacklist easily as well.

Remove plugin_googlemap2_proxy.php!
The simplest – and best – way to stop being a proxy for DoS attacks is to just remove the plugin_googlemap2_proxy.php file. This file is often located in the folder /plugins/system/ or /plugins/content/.

This will break the Joomla plugin, but be honest: who cares?! Version 2 of this plugin is deprecated, update to version 3.1.

.htaccess security for Joomla
You can easily block access to plugin_googlemap2_proxy.php with an .htaccess RewriteRule:

Open up Joomla’s default .htaccess file and locate the line RewriteEngine On.

Directly below that line, add:

RewriteRule plugin_googlemap2_proxy.php - [F,L]

This will deny any request to the URI plugin_googlemap2_proxy.php with a 403 Forbidden status code. (Updated the RewriteRule to reflect Paul’s comment)

IIS web.config protection from Joomla plugin_googlemap2_proxy.php DoS attacks
The same as the .htaccess block can be made with IIS URL Rewrite feature in the web.config file. Use the following Rewrite rule:

<rule name="block Joomla Googlemap plugin" stopProcessing="true">
  <match url=".plugin_googlemap2_proxy\.php" ignoreCase="false" />
  <action type="CustomResponse"
    statusCode="403"
    statusReason="Forbidden: Access is denied."
    statusDescription="No DDoSing remote websites!" />
</rule>

This will display an HTTP 403.0 – Forbidden status code with a message “No DDoSing remote websites!”.

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IIS Request Filtering denyUrlSequences rule
You can block requests to the plugin_googlemap2_proxy.php file with IIS’ Request Filtering too. Either in IIS’ root node, or on the website level.

In the next example, fill out a website name after config to add this Request Filtering denyUrlSequences rule to a particular website, and use /commit:webroot instead /commit:apphost

IIS root node:

AppCmd set config 
  -section:system.webserver/security/requestFiltering
  /+"denyUrlSequences.[sequence='plugin_googlemap2_proxy.php']"
  /commit:apphost

Website level:

AppCmd set config "Default Web Site"
  -section:system.webserver/security/requestFiltering
  /+"denyUrlSequences.[sequence='plugin_googlemap2_proxy.php']"
  /commit:webroot

This will display a HTTP Error 404.5 – Not Found response.

Update Joomla!, plugins and components
And last but not least…: Update Joomla!, and update all plugins and components! Frequently!

Remove unused plugins and components. The websites I inspected running this file, all still run ancient 1.5.x versions of Joomla!. Joomla 1.5.x is ancient, unsafe, vulnerable, and should be banned from the internet IMO.

After you have updated Joomla!, implement these 8 tips to tune Joomla! performance on Windows Server IIS.

Every new Joomla! version comes with new optimized PHP code, functions and settings. Use them! Always run an as high as possible Joomla! version to make use of these improvements.

8 Tips to Improve Joomla! Performance

Joomla! Googlemaps plugin plugin_googlemap2_proxy.php abusers

The following 25(!) IP addresses are responsible for millions of hits to this plugin_googlemap2_proxy.php file a day:

46.36.37.129
198.12.68.138
37.59.120.246
5.196.5.116
141.255.166.210
23.95.12.146
93.186.192.103
192.187.121.250
23.94.153.186
192.3.106.58
46.36.39.30
46.36.39.27
198.46.154.10
46.36.37.167
46.36.37.185
46.36.38.149
108.61.199.70
185.53.9.251
46.36.39.8
104.128.183.142
108.61.167.0
192.210.198.226
192.210.198.234
192.210.198.242
198.12.95.206

Unfortunately not all IP addresses are listed at services like Project Honey Pot, but I suggest you block them on your network.

Tune PHP performance: Ensure the performance of your PHP & Joomla websites by following these tips to optimize PHP realpath_cache_size and PHP OPcache.

1 reply
  1. ao
    ao says:

    Hi, thanks for the info. I’ve deleted the entire plugin directory and blocked in .htaccess, but system logs still show requests being made from /plugins/system/…….any ideas?
    thanks




    0



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    Reply

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