Linux Heap Exploitation internals

Tue, 14 Jan 2025 00:00:00 +0000

LIFO AND FIFO

LIFO (Last-In, First-Out) and FIFO (First-In, First-Out) are two fundamental methods for managing data structures, each with distinct characteristics and applications.

LIFO (Last-In, First-Out):

Structure: Commonly implemented using a stack, where the most recently added item is the first to be removed.
Analogy: Think of a stack of plates; you add and remove plates from the top.
Applications:
- Memory Management: Utilized in function call management and recursive processes, where the last called function is the first to return.
- Undo Functionality: In applications like text editors, the last action performed is the first to be undone.
- Browser History: The most recently visited page is the first to be revisited when navigating backward.

FIFO (First-In, First-Out):

Linux Heap Exploitation: Unsafe Unlink

Tue, 14 Jan 2025 00:00:00 +0000

Unsafe Unlink

Introduction

The “Unsafe Unlink” technique is a heap exploitation attack that was once quite common. It involves manipulating the unlink macro in malloc.c to remove a chunk from a bin. This attack exploits the pointer manipulation done in the unlink macro, which can lead to arbitrary code execution or other malicious activities.

When we free allocated unsorted bin, it will be freed from a doubly linked list.

A doubly linked list is a type of data structure that consists of a sequence of elements, where each element (or node) contains three parts:

Glibc on Arzedlab 🪵

Linux Heap Exploitation internals

LIFO AND FIFO

Linux Heap Exploitation: Unsafe Unlink

Unsafe Unlink

Introduction