1. Home
  2. CWE Database
  3. CWE-15
Base · Medium

CWE-15: External Control of System or Configuration Setting

One or more system settings or configuration elements can be externally controlled by a user.

CWE-15 · Base Level ·3 Mitigations

Description

One or more system settings or configuration elements can be externally controlled by a user.

Allowing external control of system settings can disrupt service or cause an application to behave in unexpected, and potentially malicious ways.

Potential Impact

Other

Varies by Context

Demonstrative Examples

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.
Bad
...sethostid(argv[1]);...
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.
Bad
...conn.setCatalog(request.getParameter("catalog"));...
In this example, an attacker could cause an error by providing a nonexistent catalog name or connect to an unauthorized portion of the database.

Mitigations & Prevention

Architecture and Design

Compartmentalize the system to have "safe" areas where trust boundaries can be unambiguously drawn. Do not allow sensitive data to go outside of the trust boundary and always be careful when interfacing with a compartment outside of the safe area. Ensure that appropriate compartmentalization is built into the system design, and the compartmentalization allows for and reinforces privilege separation functionality. Architects and designers should rely on the principle of least

ImplementationArchitecture and Design

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.

ImplementationArchitecture and Design

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 the attacker.

Detection Methods

  • Automated Static Analysis High — Automated static analysis, commonly referred to as Static Application Security Testing (SAST), can find some instances of this weakness by analyzing source code (or binary/compiled code) without having to execute it. Typically, this is done by building a model of data flow and control flow, then sea

CWE-642: External Control of Critical State Data

The product stores security-critical state information about its users, or the product itself, in a location that is acc...

CWE-610: Externally Controlled Reference to a Resource in Another Sphere

The product uses an externally controlled name or reference that resolves to a resource that is outside of the intended ...

CWE-20: Improper Input Validation

The product receives input or data, but it does not validate or incorrectly validates that the input has the ...

Taxonomy Mappings

  • 7 Pernicious Kingdoms: — Setting Manipulation
  • Software Fault Patterns: SFP25 — Tainted input to variable

Frequently Asked Questions

What is CWE-15?

CWE-15 (External Control of System or Configuration Setting) is a software weakness identified by MITRE's Common Weakness Enumeration. It is classified as a Base-level weakness. One or more system settings or configuration elements can be externally controlled by a user.

How can CWE-15 be exploited?

Attackers can exploit CWE-15 (External Control of System or Configuration Setting) to varies by context. This weakness is typically introduced during the Implementation, Implementation phase of software development.

How do I prevent CWE-15?

Key mitigations include: Compartmentalize the system to have "safe" areas where trust boundaries can be unambiguously drawn. Do not allow sensitive data to go outside of the trust boundary and always be careful when interfaci

What is the severity of CWE-15?

CWE-15 is classified as a Base-level weakness (Medium abstraction). Its actual severity depends on the specific context and how the weakness manifests in your application.