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Hardening Apache
Hardening Apache fills a huge gap in this sense, providing web administrators with a complete and yet concise book aimed to guide them from the very beginning of the installation process to the final steps of the server configuration. The author, Tony Mobily, is also the mind behind Professional Apache Security, a book published by Wrox Press which I reviewed on Slashdot about 17 months ago. Since Wrox's unfortunate closure, some of the material from that book has been moved into Hardening Apache. More specifically:
- The excellent chapter on "jailing" Apache is exactly the same;
- The chapter on XSS attacks has been slightly improved;
- The chapter on logging, which was nothing remarkable, has been greatly improved. It now includes a complete architecture to log on a remote host using encryption and a TCP/IP connection.
The first chapter of the book deals with deploying a clean and safe base installation, which will then be the grounds for adding extra functionality. Unfortunately, this task is often underestimated. What I liked in this chapter is the step-by-step guide to correctly downloading the source distribution and verifying its integrity (by checking its digital signature), as well as the clean approach to the creation of a lean, easily readable configuration file, which grants a painless maintenance. A highlight of this section is the use of Nikto to analyse and explain common weaknesses and to show how to fix them.
Chapter 2 presents some vulnerabilities and explains how to exploit them. The chapter doesn't have any "pearls of wisdom" (but it's nevertheless important to show that Apache can be vulnerable), and presents some important reference sites every web administrator should be aware of.
Chapter 3 definitely deserves a special mention: after introducing the "common" ways of logging and syslogd's architecture, the author describes a rational approach to realizing a complete logging solution which entails remote log servers, encryption of logs, and the use of a MySQL database to better organize them.
Chapter 4 is the only one which deals with the "programming" side of web security. It is not a comprehensive guide on how to write safe programs for the web, as it focuses on cross-site scripting attacks; it shows how to secure a simple and vulnerable message board written in PHP.
The following chapter talks about security modules: it presents an interesting overview of the most useful modules related to security, which will help administrators understand the importance of third-party modules and explains how to install and use some of them. I also liked Chapter 6, which deals with the installation of Apache in a secure, chrooted environment: the chapter does a great job in guiding the reader through the non-trivial steps required to get Apache, Perl and PHP working correctly in such a restricted environment.
The last chapter presents a number of powerful and well-written scripts which anybody can use to automate security and keep an eye on their web server (monitoring log growth, Apache's responsiveness, and so on).
What's to like Information throughout the book is very well focused and presented with a clean and friendly writing style. The book provides a clear and detailed walkthrough of the process of securing an Apache installation, covering both versions 1.3.x and 2.x and thus providing long lasting information. The book has lots of references and pointers to resources on the web, and - what's more important - instructions on how to read them. I also liked the "checkpoints" at the end of each chapter.
What's to consider Apart from chapter 4 on cross-site scripting attacks, the book does not cover secure web programming at all. It doesn't cover OS hardening either, which is out of scope but part of the game anyway. Going through the book requires some familiarity with Unix and Apache; otherwise you will have to resort to other books for the very basic steps.
All in all, I found this sort of "new edition" of the book by Apress to be greatly enhanced, more homogeneous and better focused than the previous book: I had been happy with Wrox's version, but I am enthusiastic about this one. This is a book which should definitely be included in any serious Apache administrator's bookshelf.
You can purchase Hardening Apache from bn.com. Slashdot welcomes readers' book reviews -- to see your own review here, read the book review guidelines, then visit the submission page.
OpenBSD's Apache has a diff of 3 or 4 thousand lines over "stock" Apache. Why not just use that?
You could also take the time to read about Hardening IIS. Come get me Mods =)
> In the end it's all about knowing your product,
In "Apache: The Definitive Guide", Ben and Peter Laurie suggest a way to learn how to build an Apache config file - start with a blank file, and start Apache. Oops, it won't start. OK, so what's it missing? Check the log files. It needs a User directive - OK, add that. Try to start. Hm, it started, but where do I put my HTML? Ah, add a DocumentRoot. And so forth.
This really doesn't take as long as it sounds - and after about 10 minutes of adding directives and restarting Apache, you'll have a lean configuration file that has just what you need in it - and you'll know how you got there, where the error logs are, and so on.
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I wish web servers wouldn't advertise their version number be default (e.g. in directory listings or HTTP headers). It's like giving an attacker an exact list of the exploits that will work on your server.
Sorry but IIS has more critical exploits in any given month than Apache has all YEAR! Why do you think Apache owns 70% of the web? Microsoft made a push in 2001 but could only get as high as 35%... at which point it tanked back to it's previous high of about 22%
This is my sig. There are many like it but this one is mine.
you're apache install will stay safe because they'll be too distracted
I coulnd't agree more with you.
The point is that if you write your config file by hand, then you HAVE TO know each directive (well, sort of).
That's part of the reason why I wrote the first chapter that way...
Merc.
(The book's author)
In "Apache: The Definitive Guide", Ben and Peter Laurie suggest a way to learn how to build an Apache config file - start with a blank file, and start Apache. Oops, it won't start. OK, so what's it missing? Check the log files. It needs a User directive - OK, add that. Try to start. Hm, it started, but where do I put my HTML? Ah, add a DocumentRoot. And so forth.
No, its not add that. Its copy that and the associated comment from the original stock config file apache provides. Now your lean config file is documented, looks just like apache's and won't confuse your successor. I generally do this with any new daemon I install that requires a config file. Note that from a security standpoint this may not be good enough if the daemon's secure options are turned off by default since you may not see any warnings in the logs.
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