COMMON WEAKNESS ENUMERATIONDraft

CWE-188

Reliance on Data/Memory Layout

The product makes invalid assumptions about how protocol data or memory is organized at a lower level, resulting in unintended program behavior.

Soyutlama

Base

Yapı

Simple

Sömürü İhtimali

Low

Problemi anla

Problem nedir?

The product makes invalid assumptions about how protocol data or memory is organized at a lower level, resulting in unintended program behavior.

Genişletilmiş açıklama

When changing platforms or protocol versions, in-memory organization of data may change in unintended ways. For example, some architectures may place local variables A and B right next to each other with A on top; some may place them next to each other with B on top; and others may add some padding to each. The padding size may vary to ensure that each variable is aligned to a proper word size. In protocol implementations, it is common to calculate an offset relative to another field to pick out a specific piece of data. Exceptional conditions, often involving new protocol versions, may add corner cases that change the data layout in an unusual way. The result can be that an implementation accesses an unintended field in the packet, treating data of one type as data of another type.

Kök neden

Problem nasıl ve ne zaman oluşur?

Yaşam döngüsü evresi

Implementation

Risk

Başarılı sömürü neye yol açar?

Modify MemoryRead Memory

Etkilenen güvenlik alanları: Integrity, Confidentiality

Can result in unintended modifications or exposure of sensitive memory.

Savunma

Nasıl önlenir ve çözülür?

Implementation · Architecture and Design

Birden fazla yaşam döngüsü evresinde uygulanacak savunma

Detay
In flat address space situations, never allow computing memory addresses as offsets from another memory address.

Architecture and Design

Mimari ve tasarım yaklaşımı

Detay
Fully specify protocol layout unambiguously, providing a structured grammar (e.g., a compilable yacc grammar).

Testing

Test ve doğrulama yaklaşımı

Detay
Testing: Test that the implementation properly handles each case in the protocol grammar.

Doğrulama

Nasıl tespit edilir?

Fuzzing

High
Fuzz testing (fuzzing) is a powerful technique for generating large numbers of diverse inputs - either randomly or algorithmically - and dynamically invoking the code with those inputs. Even with random inputs, it is often capable of generating unexpected results such as crashes, memory corruption, or resource consumption. Fuzzing effectively produces repeatable test cases that clearly indicate bugs, which helps developers to diagnose the issues.

Automated Dynamic Analysis

Moderate
Use tools that are integrated during compilation to insert runtime error-checking mechanisms related to memory safety errors, such as AddressSanitizer (ASan) for C/C++ [REF-1518].

Crafted inputs are necessary to reach the code containing the error, such as generated by fuzzers. Also, these tools may reduce performance, and they only report the error condition - not the original mistake that led to the error.