web3-smart-contract

What this skill does

Audits Solidity smart contracts and DeFi protocols against 10 high-frequency vulnerability classes: Accounting State Desynchronization, Access Control, Incomplete Code Path, Off-By-One, Oracle Manipulation, ERC4626 Attacks, Reentrancy, Flash Loan Attacks, Signature Replay, and Proxy/Upgrade Issues. Guides an auditor from pre-dive assessment through grep-pattern scanning, manual code review, Foundry proof-of-concept test writing, and severity-rated findings report generation.

When to use

• When performing a security audit of a Solidity smart contract or DeFi protocol
• When triaging a bug bounty submission involving a smart contract vulnerability
• When reviewing a protocol upgrade or new contract deployment before launch
• When estimating risk exposure of a protocol by TVL and audit history

Prerequisites

• Foundry installed:

  curl -L https://foundry.paradigm.xyz | bash
  foundryup
  

• ripgrep installed for pattern scanning:

  # Debian/Ubuntu
  apt install ripgrep
  # macOS
  brew install ripgrep
  

• (Optional) Slither static analyzer:

  pip install slither-analyzer
  

• Read access to the contract source code (Hardhat/Foundry project or Etherscan-verified source)
• Environment variable SECSKILL_CONTRACT_DIR: path to the contract source root

Inputs

Variable	Required	Description
SECSKILL_CONTRACT_DIR	required	Path to the Solidity source directory
SECSKILL_PROTOCOL_NAME	optional	Protocol name for report labeling
SECSKILL_TVL_USD	optional	Approximate TVL in USD for risk context
SECSKILL_OUTPUT_DIR	optional	Directory to save findings and PoC files (default: ./output)
SECSKILL_RPC_URL	optional	RPC URL for forked Foundry tests (e.g. mainnet fork)

Workflow

Step 1: Pre-dive assessment

Before reading code, collect signal that shapes audit priorities.

export SRC="${SECSKILL_CONTRACT_DIR:?Set SECSKILL_CONTRACT_DIR}"
export OUTDIR="${SECSKILL_OUTPUT_DIR:-./output}"
export PROTOCOL="${SECSKILL_PROTOCOL_NAME:-unknown}"
mkdir -p "$OUTDIR"

echo "===== Pre-Dive Assessment: $PROTOCOL ====="
echo "TVL (USD)    : ${SECSKILL_TVL_USD:-unknown}"
echo "Source path  : $SRC"
echo "Contract count:"
find "$SRC" -name "*.sol" | grep -v test | grep -v lib | wc -l
echo "Lines of code:"
find "$SRC" -name "*.sol" | grep -v test | grep -v lib | xargs wc -l | tail -1
echo ""
echo "[*] Check: Does the protocol have a prior audit? (check docs/audits/)"
echo "[*] Check: Is the code verified on Etherscan?"
echo "[*] Check: Is there a proxy/upgrade pattern in use?"