Design Configuration Subsystems Correctly and Distribute Safe Default Configurations

Description

The configuration of a system is the non-executable data delivered with a system that governs its dynamic behavior. The configuration is generally a set of variable values that supply information to the system in order to customize its behavior for a particular environment.

Default Configurations

This occurs when a system is shipped with a default configuration <define> <j2ee XML aspect oriented programming> that is insecure [Schneier 02: II. Default Configurations].

While this is not a programming vulnerability, it is an engineering vulnerability that is introduced in the product packaging phase of the software development life cycle.

Management or Debugging Interfaces Left Enabled

Administrative interfaces can lead to vulnerability. Sometimes the interface is left in by mistake. Sometimes it is intentional, but insecure.

In many cases, such administrative interfaces are configurable. In general, the solution to such interfaces is to configure them off. If, however, the product ships with such interfaces enabled by default, then one would reasonably classify this as a vulnerability in the product (if not in the software per se).

Administrative or management interfaces should always be restricted (via [authentication, authorization]) to proper administrators or managers.

Configuration Languages Too Complex

When the configuration "language" of a system is too complex, insufficiently expressive, contradictory, misleading, or ambiguous, it is reasonable to argue that this design will produce deployed systems that are vulnerable.

For example, avoid double or triple negatives, such as

no-read: false

When complex configuration languages are necessary,1 be sure to include in system adequate tooling for creating, managing, and checking such configuration files.

References