The Web Security Gateway is a security-centric distribution of the Apache web server, bundled with additional security modules, and configured as a front-end (reverse) HTTP proxy. The goal is to mirror most of the features of commercial web application “firewalls”, with free and Open-Source software.
The Web Security Gateway provides a configurable caching, authentication, input validation, and IDS / IPS layer for web applications. It can be placed in front of diverse web environments, and is capable of protecting almost any web application, without modifications to the code running on the protected app.
The concept of the WSGW is simple.
With Apache2, mod_filter and the integration of PCRE have made Apache extremely flexible as a content-aware application platform. Since Apache also has extensive support for proxying, it’s possible to create a front-end proxy that inspects, validates, and rewrites application content.
The WSGW can fill the gap for applications missing input validation layers, and give website administrators a first line of defense for both known and emerging attacks on web applications.
Since the WSGW will be the front-end for web traffic in a web environment, it’s also possible to integrate authentication, traffic reporting, SSL, and load balancing.
Shawn Moyer presented a talk on the WSGW concept at BlackHat USA 2006. The talk gives an overview of some of the ideas that led to the WSGW concept, and some configuration examples. You can download a copy of the talk here.
You can download WSGW here [PDF].
Or read more here.