Individual skill
web3-bug-classes
Complete reference for all 10 DeFi smart contract bug classes. Use this when hunting for specific vulnerability types, need attack patterns for accounting desync, access control, incomplete path, off-by-one, oracle manipulation, ERC4626 vaults, reentrancy, flash loans, signature replay, or proxy/upgrade bugs.
web3-bug-classes/SKILL.md
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- Last checked
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- Repository last updated
- Sep 21, 2026
- License
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- blockchain-security Repository topic
- bug-bounty Repository topic
- claude-code Repository topic
- defi Repository topic
- ethereum Repository topic
- foundry Repository topic
- immunefi Repository topic
- smart-contract-security Repository topic
- solidity Repository topic
- web3 Repository topic
- legal Derived category
- finance Derived category
- security Derived category
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Read excerpt
# BUG CLASSES — DeFi Smart Contract Vulnerabilities
10 bug classes. Each one with root cause, vulnerable code, fix, grep patterns, and real paid examples.
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## 1. ACCOUNTING STATE DESYNCHRONIZATION
> #1 Critical bug class — 28% of all Criticals on Immunefi.
> Real protocols: Yeet, Alchemix V3, Folks Finance, ResupplyFi, MetaPool
### What It Is
Two state variables are supposed to stay in sync. One code path updates variable A but forgets variable B. Later code reads both and makes decisions based on the stale B.
