the-web-application-hackers-handbook

Chapter 3 n Web Application Technologies 55
n Web mail — SquirrelMail, IlohaMail
n Photo galleries — Gallery
n Shopping carts — osCommerce, ECW-Shop
n Wikis — MediaWiki, WakkaWikki
Because PHP is free and easy to use, it has often been the language of choice
for many beginners writing web applications. Furthermore, the design and
default configuration of the PHP framework has historically made it easy for
programmers to unwittingly introduce security bugs into their code. These
factors have meant that applications written in PHP have suffered from a disproportionate
number of security vulnerabilities. In addition, several defects
have existed within the PHP platform itself that often could be exploited via
applications running on it. See Chapter 19 for details on common defects arising
in PHP applications.
Ruby on Rails
Rails 1.0 was released in 2005, with strong emphasis on Model-View-Controller
architecture. A key strength of Rails is the breakneck speed with which
fully fledged data-driven applications can be created. If a developer follows the
Rails coding style and naming conventions, Rails can autogenerate a model
for database content, controller actions for modifying it, and default views for
the application user. As with any highly functional new technology, several
vulnerabilities have been found in Ruby on Rails, including the ability to bypass
a “safe mode,” analogous to that found in PHP.
More details on recent vulnerabilities can be found here:
www.ruby-lang.org/en/security/
SQL
Structured Query Language (SQL) is used to access data in relational databases,
such as Oracle, MS-SQL server and MySQL. The vast majority of today’s web
applications employ SQL-based databases as their back-end data store, and nearly
all application functions involve interaction with these data stores in some way.
Relational databases store data in tables, each of which contains a number
of rows and columns. Each column represents a data field, such as “name” or
“e-mail address,” and each row represents an item with values assigned to some
or all of these fields.
SQL uses queries to perform common tasks such as reading, adding, updating,
and deleting data. For example, to retrieve a user’s e-mail address with a
specified name, an application might perform the following query:
select email from users where name = ‘daf’