📚 defi-security-reads

A curated knowledge base for DeFi security research — protocol analyses, essential reads, Ethereum internals, and vulnerability patterns.
Maintained by @sum1t-here · CC BY 4.0

---

Who this is for

This repo is my personal research library as I build toward professional-level smart contract auditing. Everything here has been read, studied, or actively used — not just bookmarked.

If you're on a similar path, feel free to use it as a reference. If something is wrong or missing, PRs are welcome.

---

Table of Contents

• Protocol Analyses
• Blogs & Articles to Read
• Ethereum & ERC Essentials
• Vulnerability Pattern Index
• How I Use This Repo

---

🔬 Protocol Analyses

Deep dives into protocol architecture, mechanics, and security surface.
Each entry links to my full analysis notes where available.

AMMs & DEXs

Protocol	Status	Notes
Uniswap V2	🔄 In Progress	x*y=k invariant, flash swaps, oracle manipulation surface
Uniswap V3	⬜ Planned	Concentrated liquidity, tick math, position accounting
Curve Finance	⬜ Planned	StableSwap invariant, 3pool mechanics

Lending & Borrowing

Protocol	Status	Notes
Compound V2	⬜ Planned	cToken model, interest rate model, liquidation
Aave V2/V3	⬜ Planned	aToken model, flash loans, e-mode

ERC20 Vaults & Yield

Protocol	Status	Notes
ERC-4626 Tokenized Vault Standard	⬜ Planned	Inflation attack, share price manipulation
Yearn V2	⬜ Planned	Strategy architecture, harvest mechanics

NFT & Marketplaces

Protocol	Status	Notes
OpenSea Seaport	⬜ Planned	Order validation, signature replay, fulfillment logic

Status key: ⬜ Planned · 🔄 In Progress · ✅ Complete · ❓ Needs Revisit

---

📖 Blogs & Articles to Read

Organized by topic. ✅ = read and internalized · ⬜ = queued · ⭐ = essential

Audit Methodology

Title	Author	Why it matters
⭐ The Auditor's Mindset	Joran Honig	How to think about threat modeling
⭐ How to Audit a Smart Contract	RareSkills	End-to-end audit process walkthrough
Security Assumptions in DeFi	Trail of Bits	Trust model and caller validation
On Finding Your First Bug	Officer CIA	Mindset for solo research

Vulnerability Deep Dives

Title	Author	Vulnerability
⭐ Reentrancy Attacks	OpenZeppelin	Reentrancy — post-Istanbul variants
⭐ Price Oracle Manipulation	OpenZeppelin	Oracle manipulation
Flash Loan Attacks	Quantstamp	Flash loan mechanics and risks
The Dangers of Token Integration	d-xo	Weird ERC20 behaviours
Integer Overflow Before and After Solidity 0.8	HackerNoon	Math safety
Proxies and Upgrade Patterns	OpenZeppelin	Storage collisions, initializer bugs

Exploit Post-Mortems

Exploit	Date	Loss	Key Pattern
Euler Finance Hack	Mar 2023	$197M	Flash loan + donation attack
Mango Markets	Oct 2022	$117M	Oracle price manipulation
Cream Finance	Oct 2021	$130M	Flash loan + reentrancy
Nomad Bridge	Aug 2022	$190M	Improper message validation
Ronin Bridge	Mar 2022	$625M	Compromised validator keys

Research & Tools

Title	Author	What it covers
⭐ Spearbit Public Reports	Spearbit	Learn from the best audit reports
Solodit Findings Database	Solodit	Searchable audit findings
DeFiHackLabs	SunWeb3Sec	Reproduced PoC exploits in Foundry
Immunefi Bug Bounty Reports	Immunefi	Real disclosed vulnerabilities

---

⚙️ Ethereum & ERC Essentials

The foundational layer. Everything in DeFi security traces back to one of these.

Ethereum Internals

Topic	Resource	Why it matters for security
EVM Opcodes	evm.codes	Understanding what Solidity compiles to
Storage Layout	Solidity Docs — Storage	Storage collision bugs in proxies
Memory Layout	Solidity Docs — Memory	Low-level memory bugs
ABI Encoding	ABI Spec	Calldata manipulation, signature issues
Gas Mechanics	EIP-1559	DoS via gas exhaustion
Block & Transaction	ethereum.org — Transactions	tx.origin vs msg.sender, MEV
Precompiles	evm.codes/precompiled	ecrecover misuse, signature malleability

Core ERCs — Must Know

Standard	Link	Security notes
⭐ ERC-20	EIP-20	Return value not checked, fee-on-transfer, rebasing tokens
⭐ ERC-721	EIP-721	onERC721Received reentrancy vector
ERC-1155	EIP-1155	Batch transfer reentrancy
⭐ ERC-4626	EIP-4626	Inflation attack, share rounding
ERC-2612	EIP-2612	Permit signature replay
ERC-1967	EIP-1967	Proxy storage slots
ERC-1822	EIP-1822	UUPS proxy pattern
ERC-3156	EIP-3156	Flash loan standard

Solidity Gotchas

Gotcha	Description	Where it bites
tx.origin auth	Phishing via malicious contract intermediary	Access control
Unchecked return values	transfer() on non-standard ERC20s silently fails	Token handling
Downcasting	uint256 → uint128 truncates without revert pre-0.8	Math
block.timestamp manipulation	Miners can shift ±15 seconds	Time-locked logic
Default visibility	Functions are internal by default in some versions	Access control
Uninitialized storage pointer	Points to slot 0 in older Solidity	Storage corruption
Signature malleability	ecrecover accepts two valid sigs per message	Auth bypass
Delegatecall context confusion	Executes in caller's storage context	Proxy bugs

---

🧠 Vulnerability Pattern Index

Quick-reference lookup. When I spot a pattern during an audit, I check here first.
Each entry links to a deeper note or external resource.

Access Control

• tx.origin used for authentication → Notes
• Missing onlyOwner / role check on sensitive function
• Initializer not protected — callable by anyone post-deployment
• public function that should be internal or external

Reentrancy

• External call before state update (CEI violation)
• onERC721Received / onERC1155Received callback not guarded
• Cross-function reentrancy — reenters a different function in same contract
• Read-only reentrancy — view function reads stale state during callback

Math & Precision

• Division before multiplication (precision loss)
• Unsafe casting (uint256 → uint128)
• Rounding always in user's favour (vault inflation attack)
• Unchecked arithmetic in loops

Oracle Manipulation

• Spot price read from Uniswap pair within same transaction
• TWAP window too short (manipulable within a few blocks)
• Single oracle source with no fallback
• Price not checked for staleness (Chainlink updatedAt)

Flash Loan

• Spot price readable via flash loan within one tx
• Collateral value computable from manipulable pool
• Flash loan callback modifies state that a subsequent check depends on

Token Handling

• Fee-on-transfer token not accounted for (balance diff not used)
• Rebasing token stored as raw amount
• ERC20 approve race condition
• Missing return value check on transfer() / transferFrom()

Logic & DoS

• Unbounded loop — can be gas-griefed
• External call inside loop — single failure blocks all
• Protocol assumes 1:1 token ratio that can be broken

Governance & MEV

• Governance proposal executable before timelock
• Sandwich attack possible on large AMM trades
• Frontrunnable commit-reveal scheme

---

🗂 How I Use This Repo

Before starting an audit:
Check the Protocol Analyses section for prior work on similar architectures.

During an audit:
Use the Vulnerability Pattern Index as a trigger-question checklist.

After finding a bug:
Cross-reference with Exploit Post-Mortems to understand if this is a known pattern variant.

Ongoing:
Every article I finish gets a ✅. Every new pattern I discover gets added to the index.

---

Contributing

Found a broken link, missing resource, or want to suggest something? Open an issue or PR. All constructive additions welcome.

---

License

CC BY 4.0 — free to use with attribution.

---

_{Built in public · Updated as I learn · @sum1t_here}