Book review: Basics of Web Hacking (Tools and Techniques to Attack the Web)

This is a review of The Basics of Web Hacking: Tools and Techniques to Attack the Web.

Chapter 1: The basics of Web Hacking

basicsOfWebHacking

The chapter starts with a quick introduction to some fundamental notions of web development like web applications, web servers, http protocol and a quick presentation of 2 penetration testing methodologies: The Open-Source Security Testing MethodologyManual (OSSTM) and Penetration Testing Execution Standard (PTES).

Then the author explains how the book is structured; the book will present attack vectors  around three type of targets: web server, web application and the web user and for every  type of target the same steps will be followed:

  1. Reconnaissance
  2. Scanning
  3. Exploitation
  4. Fix

The last part of the chapter is dedicated to the creation of the testing environment. As testing environment the author uses the BackTrack 5 distribution on which Damn Vulnerable Web Application (DVWA)  is installed.
The installation procedure is slightly outdated, for a newer version you can check this blog entry.

Chapter 2: Web Server Hacking

This chapter is dedicated to the hacking of the first type of target: the web server; the chapter is constructed arround the 3 steps (actually 4, but the Fix step have a dedicated chapter) that should be follow in order to sucesfully attack a web server.

The reconnaissance step is made firsly manually using commands like host and  analysis of the robots.txt file. Once some basic data about the web server is gathered, the automatic step of the reconnaissance is fulfilled using the Nmap port scanner. The authors explains how the Nmap can be updated (in case your BackTrack distribution do not have the version 6 or later) and some basic scan commands are performed (some of the flags used by the nmap command like -O, -sV, -p are explained in detail).

The scanning step is fulfilled using the Nessus tool. For Nessus, the authors explains how to install the free version, configure, run a basic scan and interpret the results. The Nikto open-source scanning tool is also very briefly presented.

The exploitation step is fulfilled using the (well known) Metasploit framework. The author starts by introducing some basic terminology like vulnerability, exploit and payload and then he presents the use of Metasploit framework in  7 easy commands: search, use, show payloads, set payload, show options, exploit. In order to explain the Metasploit commands, the author uses a hunting game analogy; for example the search command is like reviewing all possible animals that you could target, the use command is like deciding what kind of animal to hunt, the show payload is like reviewing all possible gun types, etc…

Chapter 3: Web Application Recon and Scanning

The chapter is dedicated to the web application reconnaissance and scanning. The recon part have as goal to build a map of the target web site using a web proxy. A web proxy is a application that stands between the client browser and the web application and intercepts the . The recon part can be done using automated spidering (the application starts from a page and automatically finds and requests links, submits forms, and performs any allowed action) and a manual spidering (the human operator browse through the web site). The recon is handled using the Burp Suite.

The scanning part have as goal to discover vulnerabilities. A web proxy is capable to find vulnerabilities that are detectable by inspecting the clients requests and server responses like input-based vulnerabilities targeting the server side of the application (SQL injection, OS command injection and path traversal) or input-based vulnerabilities that target the client side (XSS). The scanning part is handled using the OWASP Zed Attack Proxy (ZAP) and the author also presents briefly the Burp Scanner which is only available in the pro version of Burp Suite.      

Chapter 4: Web Exploitation with Injection

This chapter is mainly dedicated to the SQL injection vulnerabilities and Operating System Command vulnerabilities. For the SQL injection the author explains in great detail what is the SQL and how this class of  vulnerabilities can affect the target web application. To find and expose this kind of vulnerabilities the author uses the Burp Proxy, Burp Repeater and the sqlmap tool (which is a SQL injection command line tool).

The second part of the chapter is dedicated to the Operating System Command vulnerabilities.  These types of vulnerabilities are  covered in less detail compared to the SQL injection. In order to demonstrate these types of vulnerabilities the DVWA application is used but no tools that are capable to find (or to help the user to find) this kind of vulnerabilities are presented. One interesting detail for this chapter is this page containing one-liner reverse shells.

Chapter 5: Web Exploitation with Broken Authentication and Path Traversal

The author tries to broke the (web application) authentication using 2 methods: a brute force attack and an attack on the cookies generated by the web application.

For the brute force attack, a normal authentication attemp is initially intercepted  using Burp Intercept in order to find the parameters (username name and password) used for the authentication. Once this parameters have been found, the Burp Intruder product is configured to execute (repetitively) the authentication with different usernames and passwords; these usernames and passwords (called payloads) are read from external files.  The attack on the cookies it’ around the randomness of the session identifiers and the test it’s done using the Burp Sequencer product.

The last part of the chapter is dedicated to the path traversal attacks. The theorethical  part of this kind of attacks is very good covered but (as for the OS command vulnerabilities) no tool that can discover this kind of vulnerbilities is presented.

Chapter 6: Web User Hacking

This chapter is a (very) light introduction to the Cross-Site Scripting (XSS) vulnerabilities, Cross-Site Request Forgery (CSRF) vulnerabilities and to the social engineering vulnerabilities.

The good part about this chapter is that the author gives very good explanations about how this kind of attacks are triggered by the bad guys: it gives very good explanation about the difference between the XSS and CSRF vulnerabilities, it explains what is the different between a reflected and a stored XSS attack, it also gives good (web sites) references  http://XSSed.org , OWASP XSS Filter Evasion Cheat Sheet , http://www.social- engineer.org/).

On the less good part, the author do not explains how the attacker can exploit the info gathered from an XSS attack (he just says that the attacker can retrieve the user cookie using a Java script call like document.cookie).

Chapter 7: Fixes

This chapter is about how to fix the vulnerabilities presented in the previous chapters. The chapter is articulated around the same 3 possible targets: web serverweb application and the web user.

For the web server, the author proposes some strategies for server hardening: develop a repeatable hardening process, develop a process for deploying all new software updates and patches in a timely manner to the live systems, running scans and doing audits.

For the web application and the web user, the author proposes some sort of “to do” list for almost every kind of vulnerability (for example for the “Injection vulnerabilities” here is the list of things to do: Use parameterized queries, Escape malicious syntax, Make use of stored procedures, Remove unnecessary functionality on your database server, Encrypt sensitive dat).

Chapter 8: Next Steps

This small chapter contains some ideas in order to extend your knowledge regarding the security topics; what are the security grouse and events, what are the existing (security)certifications and some titles of security books.

(My) Conclusion

If you have no prior knowledge, this is very good introductory book in the web security topics; the writing style is clear and easy to follow.

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