Web Hacking: Attacks and Defense

• Authors: Stuart McClure;Saumil Shah;Shreeraj Shah
• Venue: Web Hacking: Attacks and Defense
• Year: 2002

From the Book:"We're Secure, We Have a Firewall"If only we got a nickel every time we heard a client utter this pithy phrase. On second thought, that would unfortunate as we would probably not be writing this book; we'd be sipping Pina Colada's on some white sand beach by now...For those skeptics among you, all warm and cozy next to your firewall, just remember this: over 65% of reported attacks occur over TCP port 80, the traditional web port (http://www.incidents.org). Is the web threat real? It's all too real.To Err is HumanAfter performing hundreds of security reviews over the decades, the authors have known for some time what you are about to know (if you don't already): Nothing can be truly secure. Error is at the heart of every security breach and as the saying goes: to err is human. No level of firewall, intrusion detection system (IDS), or anti-virus software will make you secure. Surprised this type of comment introduces a security book? Don't be. It is the harsh reality that must be accepted before the race to security can be started.So what should we do, just throw up our hands, turn the power off to our computers and revert back 30 years; forgetting this Internet or the modem or the computer really happened? Sure, you can do that but you would be alone in your efforts. The Internet and all it has to offer is undeniable: increased communication, increased information sharing, connecting with people of all races, creeds, colors, sexes, and intelligence without boundaries or limits. And that's just the home user's benefits. Businesses use the Internet 24 hours a day, 7 days a week, making revenue and transmitting funds aroundthe world at the blink of an eye. Anyone who denies the ubiquity and staying power of the Internet is just kidding themselves.Writing on the WallOver three years ago, one of the authors wrote a foreboding article that was indicative of things to come. The column printed on August 9, 1999 and was titled "Bane of e-commerce: We're secure: We allow only Web traffic through our firewall" (http://www.infoworld.com/articles/op/xml/99/08/09/990809opsecwatch.xml). The writing was on the security wall at that time but no one wanted to believe it, much less talk about it. They were too caught up in either hyped technologies such as Firewalls, IDS, and virtual private networks (VPN), or peripheral technologies that never hit mainstream, such as Public Key Infrastructure (PKI), Distributed Computing Environment (DCE), and single signon.So why the tremendous interest in the Web and its security now? Because hacking events are frequent in today's connected world. And people are beginning to understand how a single vulnerability in a web application can expose an entire company's jewels to an attacker (a.k.a. Code Red and Nimda worms).Book OrganizationThis book as been organized into four sections: E-Commerce Playground URLs Unraveled How do they do it? Advanced Web Kung FuThe content in each section gets progressively more advanced in its content and delivery, going from a brief web languages introduction (Chapter 1) to finding and exploiting your own buffer overflows (Chapter 14). But don't let the pace derail your learning. If you missed something, you can probably pick it up as you go along.The first sections are focused to give the reader a preliminary and then more intermediate introduction into the world of the web. In "E-Commerce Playground" we show you how the web works, its languages, applications, databases, protocols, and syntax. In "URLs Unraveled", we delve into the meaning of the URL, what is important to an attacker, how visible code can be helpful to an attacker, and we show you how mapping web sites can be critical to an attacker's repertoire.In the third section, "How do they do it?" we demystify the art of web hacking, how it is pulled off, and how simple steps at development time can eliminate a significant portion of the threat. This section is bar far the meatier of the sections in terms of information and often provides the greatest clues as to how hackers do what they do. Each chapter provides both a detailed analysis of the hack as well as a countermeasure section at the end which helps prevent the hack.In the fourth section, "Advanced Web Kung Fu," we discuss some advanced web hacking concepts, methodologies, and tools that simply cannot be missed.Finally, at the end of the book you will find Appendices that include a listing of common web ports on the Internet, cheat sheets for remote command execution and source code disclosure techniques, among other additions.