Application Security - Implementing Database Security and Auditing - page 128

Figure 5.1

The application
includes the
schema.

database-centric view, this means the application is a “fat pipe” into the data-
base, meaning that any security breach that occurs at the application layer
can immediately translate into a serious security incident at the database
level. If you choose to take this application developer-centric approach, then
the database and the data stored within it can remain exposed.
This chapter offers an alternative approach. In this approach, the data-
base still plays a central role in application architectures but is allowed to
protect itself against application misuse by an attacker. It shows you some
of the application issues you should be aware of and some of the vulnera-
bilities that may be present at the application layer. It then goes on to
explain what you can do at the database level to limit the exposure to data
access attacks that may originate from the application or that use applica-
tion credentials.

5.1 Reviewing where and how database users and

passwords are maintained

Your database has a security model, and like most security models in the
world, it is based on an authentication process and an authorization model.
The database has a set of login names that it knows. Whenever a connec-
tion to the database is made, the database gets a username and a password
and proceeds to authenticate these credentials. Once authenticated, the
database looks up the set of privileges associated with that login name—this
set determines what that connection is allowed to do.
Naturally, such a security model depends on the fact that the usernames
and passwords are maintained securely. If this is not true, then the entire