This 5 day course will give an in depth examination of a variety of current heap allocators in the context of exploit development, including glibc’s ptmalloc2, Chrome’s PartitionAlloc, JEMalloc, TCMalloc, embedded allocators such as avr-libc, newlib, or dietlibc, and those used in Linux Docker images such musl and uClibc. The lectures and labs will look at numerous ways to misuse each of these allocators in the latest versions of each.
To achieve these attacks we will have detailed examinations of the main heap structures including the thread caches, freelists, bins, malloc chunks, and arenas.
These attacks will be used to gain such primitives as:
- Having malloc return an arbitrary pointer
- Having allocated chunks overlap each other
- Returning the same allocated memory
- Having calloc return uninitialised memory
- Leaking the libc base and other sensitive information
Attacks will be constructed for a variety of heap allocators, including:
- Freelist poisoning
- Overlapping chunks
- Freeing attacker controlled pointers
- Contemporary unlink attacks
- Double frees
Course Objectives
To learn and demonstrate attacks on current heap allocators to gain exploitation primitives.
Training Outcomes
- Demonstrate understanding of the heap data structures
- Demonstrate debugging heap data structures
- Demonstrate attacks against multiple heap allocators
Who Should Attend?
- Developers
- IT Professionals
- Embedded Developers
- OS Developers
- Penetration Testers
- Software Security Auditers/Analysts
- Vulnerability Researchers
- Software Exploitation Developers
- Anyone else interested
What is required:
- An internet connection
- A browser
- webcam & microphone (optional)
- your favourite SSH tool
- PDF viewer for notes & lab guide
What will be Provided?
- Lab connection details distributed in class
- Access to VMs with laboratories
- InfoSect Swag & participation certificate (posted)
Participant Skillset
Students taking Linux Heap Exploitation should have an intermediate C Development background. They should have hands on experience in:
- C Coding Experience
- Python Coding Experience
- Linux
InfoSect’s Code Review course is a suitable prerequisite.
Class Syllabus **
Day 1 Content
• Memory Corruption
• Control Flow Hijacking
• Heap Data Structures
• The TCache
• TCache Poisoning
• TCache Poisoning in glibc 2.27 - 2.31
• Pointer Guard in glibc
• Linux Kernel SLUB Allocator
• ISO Alloc
• Safe Linking in glibc 2.32
Day 2 Content
• Revisiting SLUB
• TCache Double Free
• Fast Bins
• Fast Bin Double Free
• Double Free Mitigation Bypass
• Overlapping Chunks
• Calloc I
• Calloc II
Day 3 Content
• House of Force
• TCache House of Spirit
• Fast Bin Poisoning I
• Fast Bin Poisoning II
• Unsorted Bin LIBC Base Leak
Day 4 Content
• Scudo
• TCMalloc-1
• TCMalloc-2
• JEMalloc
• PartitionAlloc
Day 5 Content
• uClibc
• newlib
• dietlibc
• musl
• avr-libc
** subject to changes
