TetuPawnShop.sol Security Audit Report

Audit Conducted: April 2025
Auditor: Aayush

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📜 Overview

This repository contains the complete security audit for TetuPawnShop.sol, a collateralized lending contract in the Tetu Finance ecosystem. The audit focuses on the redeem() function's critical vulnerability and provides remediation guidance.

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🔍 Audit Details

📌 Scope

• Contract: TetuPawnShop.sol (commit: [hash])
• Focus: redeem() function state management vulnerability
• Severity: Critical (CVSS: 8.5)

🛠️ Tools Used

• Manual Code Review
• Slither (Static Analysis)
• Foundry (For PoC Tests)
• Solidity CEI Pattern Verification

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📝 Findings Summary

Severity	Issue	Status
Critical	Premature state change in redeem()	Fixed ✅
Medium	Missing toSend amount validation	Recommended 🔄
Low	Insufficient event logging	Optional ⏳

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🚨 Critical Vulnerability: Improper State Change

Impact

• Potential collateral theft via reentrancy-like exploitation
• Broken atomicity in redemption flow
• Estimated risk: High (Funds-at-risk)

🔧 Recommended Fix

function redeem(uint id) external nonReentrant override {
    // ...checks...
    uint toSend = _toRedeem(id);
    IERC20(...).safeTransferFrom(...);  // Interactions first
    _transferCollateral(...);
    _endPosition(pos);  // State change last
}

📬 Contact Me

For Security Discussions

✉️ Email: [[email protected]]

Professional Networks

🐦 Twitter/X: @aayushjhaaudits (DMs open for security reports)

Response Time:

• Critical Issues: <24 hours
• General Inquiries: 3-5 business days

Note: For audit-related queries, include "TetuPawnShop Audit" in the subject line.