COMMON WEAKNESS ENUMERATIONDraft

CWE-454

External Initialization of Trusted Variables or Data Stores

The product initializes critical internal variables or data stores using inputs that can be modified by untrusted actors.

Abstraction

Base

Structure

Simple

Likelihood of Exploit

Medium

Understand the problem

What is the problem?

The product initializes critical internal variables or data stores using inputs that can be modified by untrusted actors.

Extended description

A product system should be reluctant to trust variables that have been initialized outside of its trust boundary, especially if they are initialized by users. The variables may have been initialized incorrectly. If an attacker can initialize the variable, then they can influence what the vulnerable system will do.

Root cause

How and when does the problem arise?

Lifecycle phase

Architecture and Design

Lifecycle phase

Implementation

Risk

What does successful exploitation lead to?

Modify Application Data

Affected security scopes: Integrity

An attacker could gain access to and modify sensitive data or system information.

Defence

How is it prevented and fixed?

Implementation

Input Validation

Detail
A product system should be reluctant to trust variables that have been initialized outside of its trust boundary. Ensure adequate checking (e.g. input validation) is performed when relying on input from outside a trust boundary.

Architecture and Design

Architecture and design approach

Detail
Avoid any external control of variables. If necessary, restrict the variables that can be modified using an allowlist, and use a different namespace or naming convention if possible.

Verification

How is it detected?

Automated Static Analysis

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 searching for potentially-vulnerable patterns that connect "sources" (origins of input) with "sinks" (destinations where the data interacts with external components, a lower layer such as the OS, etc.)