Nginx is getting more and more used by popular website, if we look at netcraft 9.63% of internet are today using nginx based webserver, this including huge websites such as Rambler, wordpress.com ,Sourceforge.net and vkontakte.ru.
These website needs a big performance for serving millions of visitors daily if we talk about vontakte than it’s the Russian version of facebook so we can expect the number of subscribers and users with profiles and content, Nginx was firstly created for rambler back in 2004 by Igor Sysoev and distributed under the BSD-like license.
Now if your server running nginx [engine x] than there is an interesting open source adds on that you can use for your server, Naxsi a web application firewall module for nginx, here it is important to note that you can not count on any WAF for totaly secure your website but beside having all security measures this helps to improve your defense in depth strategy.
So it helps to prevent exploiting new and unknown vulnerabilities at an early stage, by looking at keywords used by hackers for conducting SQL Injections, Cross Site Scripting, Cross Site Request Forgery, Local & Remote file inclusions.
There are two reviews that are conducted the first shows how the WAF blocked a well-known vulnerabilities while the second have been conducted with IBM AppScan and the result showed several bugs even behind the WAF. This prove the importance of monitoring and how it is always necessary to fix the application layer and not counting totally on a third party security solution.
You can download and find the Naxsi reviews by following this link: http://code.google.com/p/naxsi/