The topic of website security is seldom brought up among non-programmers and

those who may not be technically inclined, yet if you operate a website, it is

an issue of substantial concern to you.

Addressed in this article is a nearly universal problem, it affects almost

every single PHP or CGI script I've ever seen. We won't delve into the

technical issues too far, this is intended for the web site owner, someone who

might install the occasional PHP file or CGI script. I will assume you are not

a software developer.

A general rule I like to follow when installing php scripts or web applications

is this: If it doesn't need to be on the web, it shouldn't be there. This is

obvious, but it has implications that are not always clear.

What we are mainly referring to is configuration and to a lesser extent,

program libraries and source code. It may also apply to files and other

resources that are controlled through a script interface. An example of this

would be scripts that charge money for downloading files or set up newsletters.

Lets start with an example, we'll call it program.php. In our example,

program.php is a database application using mysql to store information.

For our script to do it's job, it will need access to your mysql password and

user-name. It may also need access to many other program files and so-forth.

During installation, a control panel probably asked for your mysql credentials,

it may even have asked you to change the file permissions on a configuration

file of some sort. You've probably been through this type of install process at

one time or another.

What it will do next, is write your database password and other private

information to a configuration file. This usually happens without your

knowledge, it is also where our problems begin.

Most people don't catch this right away, if the configuration file is in

the same directory (or sub-directory) it is web accessible. Quite often

it is a php file, usually with write permissions turned on.

The extension .php does afford some degree of protection, under normal

circumstances these files aren't sent to a visitors browser but it is still

unsafe.

If someone makes a slight mistake in the configuration or .htaccess file, it

will dump the actual contents of "conf.php" to the users web browser, complete

with your database password and other private information.

As anyone who has been around web servers very long can tell you, this is

a common occurrence. I've personally seen it happen on several occasions.

Furthermore, many other web editing tools need to create backup files,

resulting in something like config.php.BAK or perhaps config.php.tmp.

We now have a file ripe for hackers and other would-be intruders to gain access

to your mysql database passwords as well as any other private information

kept there.

What is most alarming is that almost every single off the shelf web based

program exhibits this very problem in some form or another.

You may ask yourself why a competent software designer would do such a thing?

Why is it so common?

The answer is simplicity and market value. Customers demand software that is

easy to install. It is actually done this way for your convenience.

Scripts that store everything in one directory make it easy for you, the

website owner, to install and manage. Web software customers have come

to demand this sort of thing.

Most software designers are aware of this problem, this is why they often

choose to write configuration into a .php file, it gives you some protection at

the expense of introducing other potentially security problems we won't cover

here.

While java servlet technology provides WEB-INF/ (a secure place to store this

type of information) most PHP or CGI environments do not offer such an

environment.

Furthermore some web servers use something called "safe mode" which is a

misguided attempt to make PHP "secure", operating in this mode forces a software

developer to write insecure programs in the manner I've just outlined.

For those of you who have inspected your website, good job! you've probably

discovered you do have this problem. The next question is "What can be done"?

The correct approach is to relocate your configuration files (and any other

information that shouldn't be web accessible) to a place safely outside your

document root (sometimes called your "web folder") after you have done this,

you shouldn't be able to access the files with a web browser, not even with

a password.

I generally like to use the HOME directory, but it doesn't matter as long as

it's safely kept well away from the prying eyes of would-be hackers.

With many scripts, this is not very practical, particularly if you have already

installed them. At this point, damage control may be your only option.

If you're using apache, you can give yourself some added protection in the form

of an .htaccess file, this is still not not secure, but it's certainly better

than nothing at all. In "safe" mode, this may be your only option.

There are also things you can do via the language itself, but I won't cover

them here.

After you have done this, it is important to make a note to yourself about it.

When backing up your website, you will need to include not only the web pages,

but these other files that you now have safely tucked outside your web

directory.

If you are unable to solve the problem, (for example the web script won't allow

you to locate these files elsewhere) Simply being aware of it can go a long way

toward protecting your website from future attackers. Now that you know, you

can keep an eye out for any backup files that may have been created by other

tools.

Try not to be too tough on whoever wrote the program, chances are they chose

to do it this way for the convenience of their users. I can attest from first

hand experience, if you don't store configuration data this way, customers

can become annoyed and rarely understand your reasoning.