COMMON WEAKNESS ENUMERATIONIncomplete

CWE-128

Wrap-around Error

Wrap around errors occur whenever a value is incremented past the maximum value for its type and therefore "wraps around" to a very small, negative, or undefined value.

Soyutlama

Base

Yapı

Simple

Sömürü İhtimali

Medium

Problemi anla

Problem nedir?

Wrap around errors occur whenever a value is incremented past the maximum value for its type and therefore "wraps around" to a very small, negative, or undefined value.

Kök neden

Problem nasıl ve ne zaman oluşur?

Yaşam döngüsü evresi

Implementation

Due to how addition is performed by computers, if a primitive is incremented past the maximum value possible for its storage space, the system will not recognize this, and therefore increment each bit as if it still had extra space. Because of how negative numbers are represented in binary, primitives interpreted as signed may "wrap" to very large negative values.

Risk

Başarılı sömürü neye yol açar?

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

Etkilenen güvenlik alanları: Availability

This weakness will generally lead to undefined behavior and therefore crashes. In the case of overflows involving loop index variables, the likelihood of infinite loops is also high.
Modify Memory

Etkilenen güvenlik alanları: Integrity

If the value in question is important to data (as opposed to flow), simple data corruption has occurred. Also, if the wrap around results in other conditions such as buffer overflows, further memory corruption may occur.
Execute Unauthorized Code or CommandsBypass Protection Mechanism

Etkilenen güvenlik alanları: Confidentiality, Availability, Access Control

This weakness can sometimes trigger buffer overflows which can be used to execute arbitrary code. This is usually outside the scope of a program's implicit security policy.

Savunma

Nasıl önlenir ve çözülür?

Tüm evreler

Genel azaltım ve savunma yaklaşımı

Detay
Requirements specification: The choice could be made to use a language that is not susceptible to these issues.

Architecture and Design

Mimari ve tasarım yaklaşımı

Detay
Provide clear upper and lower bounds on the scale of any protocols designed.

Implementation

Uygulama aşaması savunması

Detay
Perform validation on all incremented variables to ensure that they remain within reasonable bounds.

Doğrulama

Nasıl tespit edilir?

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.)