15 (Weakness Base)

Compartmentalize your system and determine where the trust boundaries exist. Any input/control outside the trust boundary should be treated as potentially hostile.

Because setting manipulation covers a diverse set of functions, any attempt at illustrating it will inevitably be incomplete. Rather than searching for a tight-knit relationship between the functions addressed in the setting manipulation category, take a step back and consider the sorts of system values that an attacker should not be allowed to control.

In general, do not allow user-provided or otherwise untrusted data to control sensitive values. The leverage that an attacker gains by controlling these values is not always immediately obvious, but do not underestimate the creativity of your attacker.

The following C code accepts a number as one of its command line parameters and sets it as the host ID of the current machine.

C Example:

Although a process must be privileged to successfully invoke sethostid(), unprivileged users may be able to invoke the program. The code in this example allows user input to directly control the value of a system setting. If an attacker provides a malicious value for host ID, the attacker can misidentify the affected machine on the network or cause other unintended behavior.

The following Java code snippet reads a string from an HttpServletRequest and sets it as the active catalog for a database Connection.

Java Example:

In this example, an attacker could cause an error by providing a nonexistent catalog name or connect to an unauthorized portion of the database.

Setting manipulation vulnerabilities occur when an attacker can control values that govern the behavior of the system, manage specific resources, or in some way affect the functionality of the application.

7 Pernicious Kingdoms - Setting Manipulation