COMMON WEAKNESS ENUMERATIONIncomplete

CWE-192

Integer Coercion Error

Integer coercion refers to a set of flaws pertaining to the type casting, extension, or truncation of primitive data types.

Abstraction

Variant

Structure

Simple

Likelihood of Exploit

Medium

Understand the problem

What is the problem?

Integer coercion refers to a set of flaws pertaining to the type casting, extension, or truncation of primitive data types.

Extended description

Several flaws fall under the category of integer coercion errors. For the most part, these errors in and of themselves result only in availability and data integrity issues. However, in some circumstances, they may result in other, more complicated security related flaws, such as buffer overflow conditions.

Root cause

How and when does the problem arise?

Lifecycle phase

Implementation

Risk

What does successful exploitation lead to?

DoS: Resource Consumption (CPU)DoS: Resource Consumption (Memory)DoS: Crash, Exit, or Restart

Affected security scopes: Availability

Integer coercion often leads to undefined states of execution resulting in infinite loops or crashes.
Execute Unauthorized Code or Commands

Affected security scopes: Integrity, Confidentiality, Availability

In some cases, integer coercion errors can lead to exploitable buffer overflow conditions, resulting in the execution of arbitrary code.
Other

Affected security scopes: Integrity, Other

Integer coercion errors result in an incorrect value being stored for the variable in question.

Defence

How is it prevented and fixed?

Requirements

Security requirement

Detail
A language which throws exceptions on ambiguous data casts might be chosen.

Architecture and Design

Architecture and design approach

Detail
Design objects and program flow such that multiple or complex casts are unnecessary

Implementation

Implementation-phase defence

Detail
Ensure that any data type casting that you must used is entirely understood in order to reduce the plausibility of error in use.

Verification

How is it detected?

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 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.)