Version-Specific Techniques Matrix

Overview

This page provides a comprehensive matrix showing which heap exploitation techniques work with which glibc versions. Understanding technique compatibility is essential for:

CTF challenge exploitation
Vulnerability assessment
Exploit development
Security research

Always verify the glibc version of your target before selecting an exploitation technique. Using an incompatible technique will result in crashes or malloc errors.

Quick Reference Legend

Symbol	Meaning
✅	Technique works on this version
❌	Technique patched/doesn’t work
🟡	Technique requires modifications
🆕	Technique introduced in this version

Complete Technique Compatibility Matrix

Basic Techniques

Technique	2.23	2.24	2.27	2.31	2.32	2.33	2.34	2.35+
first_fit	✅	✅	✅	✅	✅	✅	✅	✅
calc_tcache_idx	❌	❌	✅	✅	✅	✅	✅	✅

Basic techniques like first_fit demonstrate allocator behavior and work across all versions. calc_tcache_idx requires tcache support (2.26+).

Fastbin Attacks

Technique	2.23	2.24	2.27	2.31	2.32	2.33	2.34	2.35+
fastbin_dup	✅	✅	✅	✅	✅	✅	✅	✅
fastbin_dup_into_stack	✅	✅	✅	✅	✅	✅	✅	✅
fastbin_dup_consolidate	✅	✅	✅	✅	✅	✅	✅	✅
fastbin_reverse_into_tcache	❌	❌	🆕	✅	✅	✅	✅	✅

Fastbin attacks remain viable across versions but may require adaptations for tcache interaction in 2.27+.

Unlink and Chunk Overlap

Technique	2.23	2.24	2.27	2.31	2.32	2.33	2.34	2.35+	Patch
unsafe_unlink	✅	✅	✅	✅	✅	✅	✅	✅	-
overlapping_chunks	✅	✅	✅	❌	❌	❌	❌	❌	b90ddd08
overlapping_chunks_2	✅	✅	✅	❌	❌	❌	❌	❌	b90ddd08
mmap_overlapping_chunks	✅	✅	✅	✅	✅	✅	✅	✅	-

Both overlapping_chunks techniques were patched in glibc 2.29 due to enhanced size consistency checks.

House Techniques

Technique	2.23	2.24	2.27	2.31	2.32	2.33	2.34	2.35+	Patch
house_of_spirit	✅	✅	✅	✅	✅	✅	✅	✅	-
house_of_lore	✅	✅	✅	✅	✅	✅	✅	✅	-
house_of_force	✅	✅	✅	❌	❌	❌	❌	❌	30a17d8c
house_of_einherjar	✅	✅	✅	✅	✅	✅	✅	✅	-
house_of_orange	✅	❌	❌	❌	❌	❌	❌	❌	91e7cf98
house_of_roman	✅	✅	✅	❌	❌	❌	❌	❌	b90ddd08
house_of_mind_fastbin	✅	✅	✅	✅	✅	✅	✅	✅	-
house_of_storm	✅	✅	✅	❌	❌	❌	❌	❌	-
house_of_gods	✅	✅	❌	❌	❌	❌	❌	❌	-
house_of_io	❌	❌	❌	🆕	✅	✅	❌	❌	-

Modern House Techniques (2.26+)

Technique	2.27	2.31	2.32	2.33	2.34	2.35	2.36+	2.39+
house_of_water	❌	❌	❌	❌	❌	❌	🆕	✅
house_of_tangerine	❌	❌	❌	❌	❌	❌	❌	🆕
house_of_botcake	🆕	✅	✅	✅	✅	✅	✅	✅

house_of_water and house_of_tangerine are cutting-edge techniques that work around modern protections.

Tcache Attacks

Technique	2.23	2.24	2.27	2.31	2.32	2.33	2.34	2.35+	Notes
tcache_dup (obsolete)	❌	❌	🆕	❌	❌	❌	❌	❌	Patched 2.29
tcache_poisoning	❌	❌	🆕	✅	🟡	🟡	🟡	🟡	Requires heap leak 2.32+
tcache_house_of_spirit	❌	❌	🆕	✅	✅	✅	✅	✅	-
tcache_stashing_unlink_attack	❌	❌	🆕	✅	✅	✅	✅	✅	-
tcache_metadata_poisoning	❌	❌	🆕	✅	✅	✅	✅	✅	-
tcache_relative_write	❌	❌	❌	❌	❌	❌	❌	✅	2.30+

tcache_poisoning requires a heap leak starting from glibc 2.32 due to safe-linking protection.

Bin Attacks

Technique	2.23	2.24	2.27	2.31	2.32	2.33	2.34	2.35+	Patch
unsorted_bin_into_stack	✅	✅	✅	❌	❌	❌	❌	❌	b90ddd08
unsorted_bin_attack	✅	✅	✅	❌	❌	❌	❌	❌	b90ddd08
large_bin_attack	✅	✅	✅	✅	✅	✅	✅	✅	-

Special Techniques

Technique	2.23	2.24	2.27	2.31	2.32	2.33	2.34	2.35+
poison_null_byte	✅	✅	✅	✅	✅	✅	✅	✅
decrypt_safe_linking	❌	❌	❌	❌	🆕	✅	✅	✅
safe_link_double_protect	❌	❌	❌	❌	🟡	🟡	🟡	✅
sysmalloc_int_free	❌	❌	❌	❌	❌	❌	❌	✅

Version-Specific Adaptations

glibc 2.23 - The “Golden Age”

Why it’s popular:

Most techniques work without modification
Minimal protections
Common in older CTF challenges
Good for learning fundamentals

Available Techniques:

fastbin_dup, fastbin_dup_into_stack, unsafe_unlink, 
house_of_spirit, poison_null_byte, house_of_lore,
overlapping_chunks, overlapping_chunks_2, house_of_force,
unsorted_bin_into_stack, unsorted_bin_attack, house_of_orange,
house_of_roman, house_of_gods

glibc 2.27 - tcache Era Begins

Major Change:

tcache enabled by default (Ubuntu builds)
New attack surface
Fastbin behavior changes

New Techniques:

tcache_dup (later patched), tcache_poisoning,
tcache_house_of_spirit, tcache_stashing_unlink_attack,
fastbin_reverse_into_tcache, house_of_botcake

Patched:

house_of_gods (< 2.27)

glibc 2.29 - The Great Patching

Major Changes:

Comprehensive size consistency checks
Many classic techniques patched

Patched Techniques:

overlapping_chunks, overlapping_chunks_2, house_of_force,
unsorted_bin_into_stack, unsorted_bin_attack, house_of_roman,
house_of_storm, tcache_dup

Still Working:

fastbin attacks, tcache attacks, large_bin_attack,
house_of_spirit, house_of_lore, house_of_einherjar,
poison_null_byte, unsafe_unlink

glibc 2.32 - Safe-Linking

Major Change:

Pointer obfuscation in tcache/fastbins
Heap leak becomes essential

Impact:

tcache_poisoning now requires heap leak
All blind tcache attacks impossible
New techniques needed

New Techniques:

decrypt_safe_linking, safe_link_double_protect

Adaptation Required:

tcache_poisoning (🟡 requires heap leak)
fastbin_dup (🟡 requires decryption)

glibc 2.35+ - Modern Era

Status:

Most stable modern version
Many techniques updated for compatibility
Good target for modern CTF challenges

Working Techniques:

All fastbin attacks, most tcache attacks, large_bin_attack,
house_of_spirit, house_of_lore, house_of_einherjar,
house_of_mind_fastbin, house_of_botcake, poison_null_byte,
unsafe_unlink, mmap_overlapping_chunks

glibc 2.39+ - Cutting Edge

New Techniques:

house_of_tangerine, sysmalloc_int_free

Status:

Actively developed
New techniques being researched
Some experimental techniques

Practical Selection Guide

For CTF Players

Easy (2.23-2.27)
Medium (2.29-2.31)
Hard (2.32+)

Target Version: glibc 2.23-2.27Recommended Techniques:

fastbin_dup
house_of_spirit
unsorted_bin_attack (< 2.29)
house_of_force (< 2.29)
poison_null_byte

Learning Path:

Start with first_fit and basic allocator behavior
Practice fastbin attacks
Try house techniques
Attempt unsorted bin exploitation

Quick Version Check

To check the glibc version of a binary:

# Method 1: Check linked libc
ldd ./binary | grep libc

# Method 2: Run the binary and check version
./binary --version

# Method 3: Extract from binary
strings ./binary | grep GLIBC_

# Method 4: Use checksec tools
checksec --file=./binary

Testing Technique Compatibility

Test a Technique on Multiple Versions

#!/bin/bash
# Test fastbin_dup across versions

for version in 2.23 2.27 2.31 2.35 2.39; do
  echo "Testing glibc $version"
  H2H_USE_SYSTEM_LIBC=N make v$version
  ./glibc_$version/fastbin_dup
  echo "---"
done

Verify Technique Availability

# Check if a technique exists for a version
ls -la glibc_2.35/ | grep house_of_force  # Won't exist - patched
ls -la glibc_2.23/ | grep house_of_force  # Exists

Notable CTF Challenges by Version

glibc 2.23 Challenges

PlaidCTF 2015 - plaiddb (poison_null_byte)
Hitcon 2016 - houseoforange (house_of_orange)
Hitcon 2016 - SleepyHolder (fastbin_dup_consolidate)
Seccon 2016 - tinypad (house_of_einherjar)

glibc 2.27+ Challenges

Hitcon 2019 - one punch man (tcache_stashing_unlink_attack)
0ctf 2018 - heapstorm2 (large_bin_attack)
37c3 Potluck 2023 - Tamagoyaki (house_of_water, safe_link_double_protect)
PicoCTF 2024 - high frequency troubles (house_of_tangerine)

Summary Table: Major Protection Milestones

Version	Major Protection	Techniques Patched	New Techniques
2.26	tcache, unlink checks	-	tcache attacks
2.27	Fastbin checks, double-free	tcache_dup	house_of_botcake
2.29	Size consistency	7+ classic techniques	-
2.32	Safe-linking	Blind tcache attacks	decrypt_safe_linking
2.36+	Ongoing hardening	-	house_of_water, house_of_tangerine

Additional Resources

Version Compatibility Guide
glibc Changelog
[Getting Started with how2heap/quickstart)
[Technique Reference/reference/all-techniques)

Get Started

Fundamentals

Fastbin Techniques

Tcache Techniques

House Techniques

Bin & Chunk Manipulation

Advanced Techniques

Glibc Versions

Tools & Resources

Version-Specific Techniques Matrix

Overview

Quick Reference Legend

Complete Technique Compatibility Matrix

Basic Techniques

Fastbin Attacks

Unlink and Chunk Overlap

House Techniques

Modern House Techniques (2.26+)

Tcache Attacks

Bin Attacks

Special Techniques

Version-Specific Adaptations

glibc 2.23 - The “Golden Age”

glibc 2.27 - tcache Era Begins

glibc 2.29 - The Great Patching

glibc 2.32 - Safe-Linking

glibc 2.35+ - Modern Era

glibc 2.39+ - Cutting Edge

Practical Selection Guide

For CTF Players

Quick Version Check

Testing Technique Compatibility

Test a Technique on Multiple Versions

Verify Technique Availability

Notable CTF Challenges by Version

glibc 2.23 Challenges

glibc 2.27+ Challenges

Summary Table: Major Protection Milestones

Additional Resources

Build docs developers (and LLMs) love

Get Started

Fundamentals

Fastbin Techniques

Tcache Techniques

House Techniques

Bin & Chunk Manipulation

Advanced Techniques

Glibc Versions

Tools & Resources

​Overview

​Quick Reference Legend

​Complete Technique Compatibility Matrix

​Basic Techniques

​Fastbin Attacks

​Unlink and Chunk Overlap

​House Techniques

​Modern House Techniques (2.26+)

​Tcache Attacks

​Bin Attacks

​Special Techniques

​Version-Specific Adaptations

​glibc 2.23 - The “Golden Age”

​glibc 2.27 - tcache Era Begins

​glibc 2.29 - The Great Patching

​glibc 2.32 - Safe-Linking

​glibc 2.35+ - Modern Era

​glibc 2.39+ - Cutting Edge

​Practical Selection Guide

​For CTF Players

​Quick Version Check

​Testing Technique Compatibility

​Test a Technique on Multiple Versions

​Verify Technique Availability

​Notable CTF Challenges by Version

​glibc 2.23 Challenges

​glibc 2.27+ Challenges

​Summary Table: Major Protection Milestones

​Additional Resources

Build docs developers (and LLMs) love

Overview

Quick Reference Legend

Complete Technique Compatibility Matrix

Basic Techniques

Fastbin Attacks

Unlink and Chunk Overlap

House Techniques

Modern House Techniques (2.26+)

Tcache Attacks

Bin Attacks

Special Techniques

Version-Specific Adaptations

glibc 2.23 - The “Golden Age”

glibc 2.27 - tcache Era Begins

glibc 2.29 - The Great Patching

glibc 2.32 - Safe-Linking

glibc 2.35+ - Modern Era

glibc 2.39+ - Cutting Edge

Practical Selection Guide

For CTF Players

Quick Version Check

Testing Technique Compatibility

Test a Technique on Multiple Versions

Verify Technique Availability

Notable CTF Challenges by Version

glibc 2.23 Challenges

glibc 2.27+ Challenges

Summary Table: Major Protection Milestones

Additional Resources