mev-beta/docs/reports/security_audit_report.md

MEV Bot Security Audit Report

Project: MEV Beta Bot
Date: September 15, 2025
Auditor: Claude Code
Version: 1.0

Executive Summary

This comprehensive security audit of the MEV Bot codebase identified several critical vulnerabilities and security concerns that require immediate attention. The analysis covered security-critical components including key management, arbitrage logic, event processing, and configuration management.

Overall Risk Assessment: HIGH

The codebase contains significant security vulnerabilities that could lead to:

• Private key exposure and theft
• Unauthorized transaction execution
• Financial losses through MEV exploits
• System compromise through injection attacks

Critical Issues Found

1. CRITICAL: Hardcoded Secrets and Key Management Issues

Location: /config/config.yaml:90
Severity: CRITICAL
Risk: Private key exposure, unauthorized access

Finding:

# Private key for transaction signing (DO NOT COMMIT TO VERSION CONTROL)
private_key: "${ETHEREUM_PRIVATE_KEY}"

Issues:

• Comment explicitly warns against committing private keys, but configuration structure still allows it
• No validation that private key is properly sourced from environment
• Configuration files contain placeholder private key references that could be accidentally populated

Recommendation:

• Implement mandatory validation that private keys come from secure environment variables only
• Add configuration validation to reject any hardcoded private key values
• Use hardware security modules (HSMs) or secure enclaves for production deployments

2. CRITICAL: Weak Salt in Key Derivation

Location: /pkg/security/keymanager.go:724
Severity: CRITICAL
Risk: Cryptographic weakness, key compromise

Finding:

func deriveEncryptionKey(masterKey string) ([]byte, error) {
    salt := []byte("mev-bot-salt-2023") // In production, use a proper salt

Issues:

• Fixed, predictable salt used for key derivation
• Salt is hardcoded in source code
• Comment acknowledges this is not production-ready
• Vulnerable to rainbow table attacks

Recommendation:

• Generate cryptographically secure random salts for each key derivation
• Store salts securely alongside encrypted keys
• Use PBKDF2, scrypt, or Argon2 with appropriate iteration counts

3. CRITICAL: Incomplete Contract Implementation

Location: /pkg/arbitrage/executor.go:335
Severity: CRITICAL
Risk: Non-functional arbitrage execution, financial losses

Finding:

// For now, return an error indicating this needs actual contract deployment
return nil, fmt.Errorf("flash swap contract execution not implemented - contracts need to be deployed first")

Issues:

• Core arbitrage execution is not implemented
• Returns placeholder error instead of executing trades
• Could lead to false confidence in system functionality
• Production deployment would fail silently

Recommendation:

• Complete smart contract implementation before production deployment
• Add comprehensive integration tests with real contracts
• Implement proper error handling for contract failures

4. HIGH: Input Validation Vulnerabilities

Location: /pkg/events/parser.go (Multiple functions)
Severity: HIGH
Risk: Buffer overflow, injection attacks, system compromise

Finding:

// Parse ABI-encoded parameters (lines 541-561)
amountIn := new(big.Int).SetBytes(data[0:32])
amountOutMin := new(big.Int).SetBytes(data[32:64])

Issues:

• Insufficient bounds checking on transaction data parsing
• Direct byte slice access without length validation
• Potential for buffer overflows with malformed input
• Missing validation for ABI-encoded parameter structure

Recommendation:

• Implement comprehensive input validation for all transaction parsing
• Add bounds checking before slice operations
• Use safe ABI decoding libraries
• Validate all external data sources

5. HIGH: Race Conditions in Concurrent Processing

Location: /pkg/scanner/concurrent.go (Multiple locations)
Severity: HIGH
Risk: Data corruption, inconsistent state, failed transactions

Finding:

// Lines 913-960: Cache updates without proper synchronization
s.cacheMutex.Lock()
defer s.cacheMutex.Unlock()
// Complex operations between lock/unlock

Issues:

• Cache operations span large code blocks while holding locks
• Potential for deadlocks with nested lock acquisitions
• Race conditions in pool data updates
• Inconsistent state during concurrent arbitrage execution

Recommendation:

• Minimize lock duration and scope
• Use atomic operations where appropriate
• Implement proper transaction isolation
• Add deadlock detection and recovery

6. HIGH: Insecure RPC Endpoint Configuration

Location: /pkg/scanner/concurrent.go:849
Severity: HIGH
Risk: Credential exposure, man-in-the-middle attacks

Finding:

client, err := ethclient.Dial("wss://arbitrum-mainnet.core.chainstack.com/f69d14406bc00700da9b936504e1a870")

Issues:

• Hardcoded RPC endpoint with potential API key in URL
• No TLS certificate validation
• Credentials exposed in source code
• No fallback mechanism for endpoint failures

Recommendation:

• Move all RPC endpoints to secure configuration
• Implement proper TLS certificate validation
• Use secure credential management
• Add endpoint rotation and failover logic

Medium Risk Issues

7. MEDIUM: Insufficient Error Handling

Location: Multiple files
Risk: Information disclosure, system instability

• Error messages leak internal system details
• Panic conditions not properly handled
• Missing timeout handling in critical operations
• Insufficient logging for security events

8. MEDIUM: Missing Rate Limiting Implementation

Location: /pkg/security/keymanager.go:576
Risk: Denial of service, resource exhaustion

func (km *KeyManager) checkRateLimit(address common.Address) error {
    // Implementation would track signing rates per key
    // For now, return nil (rate limiting not implemented)
    return nil
}

9. MEDIUM: Weak Gas Price Management

Location: /pkg/arbitrage/executor.go:362
Risk: Transaction failures, MEV losses

• No protection against gas price manipulation
• Fixed gas price premiums regardless of network conditions
• No maximum gas price validation

Compilation and Build Issues

Critical Build Failures

1. Security Package Test Failures:

   pkg/security/keymanager_test.go:322:30: cannot use 10000000000000000000 (untyped int constant) as int64 value in argument to big.NewInt (overflows)
   

2. Missing Dependencies:

   pkg/oracle/price_oracle.go:204:13: not enough arguments in call to uniswap.NewUniswapV3Pricing
   

3. Type Mismatches:

   pkg/contracts/executor.go:105:49: cannot use params (variable of struct type interfaces.IArbitrageArbitrageParams) as arbitrage.IArbitrageArbitrageParams
   

Code Quality Assessment

Positive Security Practices

• Use of AES-GCM for key encryption
• Structured logging implementation
• Input validation framework (partially implemented)
• Audit logging for key operations
• Transaction signing with proper nonce management

Areas Requiring Improvement

• Test Coverage: Estimated at ~40% for security-critical components
• Documentation: Missing security considerations and threat model
• Error Handling: Inconsistent error wrapping and context
• Memory Management: Potential memory leaks in long-running processes

Production Readiness Assessment

Blockers for Production Deployment

1. Smart Contract Implementation: Core arbitrage contracts not deployed
2. Key Management: Insecure key derivation and storage
3. Build Issues: Multiple compilation failures
4. Security Vulnerabilities: Critical issues require resolution

Recommendation: NOT READY FOR PRODUCTION

Remediation Roadmap

Phase 1: Critical Issues (1-2 weeks)

1. Fix key derivation salt generation
2. Implement proper input validation
3. Complete smart contract deployment
4. Resolve all compilation errors

Phase 2: High Priority Issues (2-3 weeks)

1. Implement secure RPC endpoint management
2. Fix race conditions in concurrent processing
3. Add comprehensive rate limiting
4. Enhance error handling and logging

Phase 3: Security Hardening (1-2 weeks)

1. Security testing and penetration testing
2. Code review and audit remediation
3. Documentation and security procedures
4. Production deployment preparation

Security Controls Recommendations

Immediate Actions Required

1. Environment Variable Validation:

   func validateRequiredEnvVars() error {
       required := []string{"MEV_BOT_ENCRYPTION_KEY", "ARBITRUM_RPC_ENDPOINT"}
       for _, env := range required {
           if os.Getenv(env) == "" {
               return fmt.Errorf("required environment variable %s is not set", env)
           }
       }
       return nil
   }
   

2. Secure Key Derivation:

   func deriveEncryptionKey(masterKey string) ([]byte, error) {
       salt := make([]byte, 32)
       if _, err := rand.Read(salt); err != nil {
           return nil, fmt.Errorf("failed to generate salt: %w", err)
       }
       return scrypt.Key([]byte(masterKey), salt, 32768, 8, 1, 32)
   }
   

3. Input Validation:

   func validateTransactionData(data []byte) error {
       if len(data) < 4 {
           return fmt.Errorf("insufficient transaction data length: %d", len(data))
       }
       if len(data) > maxTransactionDataSize {
           return fmt.Errorf("transaction data too large: %d", len(data))
       }
       return nil
   }
   

Conclusion

The MEV Bot codebase demonstrates good architectural patterns but contains critical security vulnerabilities that must be addressed before production deployment. The key management system, while comprehensive in design, has fundamental cryptographic weaknesses that could lead to private key compromise.

The incomplete smart contract implementation represents the most immediate blocker to functionality, while the security issues represent the highest risk to user funds and system integrity.

Recommendation: Address all critical and high-severity issues before considering production deployment. Implement a comprehensive security testing program and consider engaging external security auditors for final validation.

Appendix A: Security Checklist

• Replace hardcoded salt with secure random generation
• Implement complete input validation for all external data
• Complete smart contract implementation and deployment
• Fix all compilation errors and build issues
• Implement secure RPC endpoint management
• Add comprehensive rate limiting and DOS protection
• Implement proper error handling and logging
• Add security testing and monitoring
• Create incident response procedures
• Document security architecture and threat model

Appendix B: File Locations for Critical Issues

Issue	File	Line(s)	Severity
Hardcoded salt	/pkg/security/keymanager.go	724	CRITICAL
Incomplete contract	/pkg/arbitrage/executor.go	335	CRITICAL
Hardcoded RPC endpoint	/pkg/scanner/concurrent.go	849	HIGH
Input validation	/pkg/events/parser.go	541-561	HIGH
Race conditions	/pkg/scanner/concurrent.go	913-960	HIGH
Rate limiting	/pkg/security/keymanager.go	576	MEDIUM

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Report Generated: September 15, 2025
Next Review: After remediation of critical issues
Contact: security@fraktal.com for questions regarding this audit