COMMON WEAKNESS ENUMERATIONIncomplete

CWE-468

Incorrect Pointer Scaling

In C and C++, one may often accidentally refer to the wrong memory due to the semantics of when math operations are implicitly scaled.

Abstraction

Base

Structure

Simple

Likelihood of Exploit

Medium

Understand the problem

What is the problem?

In C and C++, one may often accidentally refer to the wrong memory due to the semantics of when math operations are implicitly scaled.

Root cause

How and when does the problem arise?

Lifecycle phase

Implementation

Programmers may try to index from a pointer by adding a number of bytes. This is incorrect because C and C++ implicitly scale the operand by the size of the data type.

Risk

What does successful exploitation lead to?

Read MemoryModify Memory

Affected security scopes: Confidentiality, Integrity

Incorrect pointer scaling will often result in buffer overflow conditions. Confidentiality can be compromised if the weakness is in the context of a buffer over-read or under-read.

Defence

How is it prevented and fixed?

Architecture and Design

Architecture and design approach

Detail
Use a platform with high-level memory abstractions.

Implementation

Implementation-phase defence

Detail
Always use array indexing instead of direct pointer manipulation.

Architecture and Design

Architecture and design approach

Detail
Use technologies for preventing buffer overflows.

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.)