Web2 vs Web3 Bug Bounty Explained Simply

Web2 vs Web3 Bug Bounty - What’s the Real Difference?
Bug bounty hunting is changing fast
Security researchers are no longer limited to testing websites and APIs only.
With Web3, blockchain, and smart contracts, the attack surface is much bigger and the rewards can be huge

Let’s break down the real difference between Web2 and Web3 bug bounty in a simple and clear way

Web2 Bug Bounty (Traditional Internet)​

Web2 bug bounty focuses on the classic internet infrastructure that we all use every day.

What Do You Test?​

• Websites & Web applications
• APIs & backend servers
• Mobile apps
• Cloud services & infrastructure

Common Web2 Vulnerabilities​

• SQL Injection (SQLi)
• XSS (Cross-Site Scripting)
• IDOR (Broken Access Control)
• Authentication Bypass
• SSRF & RCE

Simple Example (IDOR)​

If a banking website lets you change: user_id=102 → user_id=103
and you can see another user’s data…

That’s a Critical IDOR vulnerability

Bug Impact​

• Sensitive data leaks
• Account takeover
• Full server compromise

Popular Web2 Bug Bounty Platforms​

• HackerOne
• Bugcrowd
• Intigriti

Skills You Need​

• Web security fundamentals
• API testing
• Business logic flaws

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Web3 Bug Bounty (Blockchain Era)​

Web3 bug bounty targets decentralized systems where bugs can directly cause real money loss

What Do You Test?​

• Smart contracts
• DeFi protocols
• Crypto wallets
• DApps
• Bridges & price oracles

Common Web3 Vulnerabilities​

• Reentrancy attacks
• Integer overflow / underflow
• Flash loan attacks
• Price oracle manipulation
• Access control bugs

Simple Example (Reentrancy)​

A DeFi lending contract allows multiple withdrawals before updating the balance.
Attacker drains the protocol using a reentrancy loop

Code Example (Vulnerable Solidity)​

function withdraw(uint amount) public {
    require(balances[msg.sender] >= amount);
    msg.sender.call{value: amount}("");
    balances[msg.sender] -= amount;
}

The balance update happens after sending ETH - perfect for a reentrancy attack.

Bug Impact​

• Direct crypto loss
• Protocol collapse
• Permanent on-chain damage (no rollback )

Popular Web3 Bug Bounty Platforms​

• Immunefi
• HackerOne (Web3 programs)
• Code4rena

Skills You Need​

• Solidity & smart contract logic
• Blockchain fundamentals
• Deep understanding of DeFi mechanics

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Web2 vs Web3 Bug Bounty - Quick Comparison​

Feature	Web2	Web3
Core Target	Websites & APIs	Smart Contracts
Languages	JS, PHP, Python	Solidity, Rust
Can You Patch Bugs?	Yes	No
Main Impact	Data loss	Direct money loss
Difficulty	Medium	High
Rewards	Good	Very High

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Which One Should You Choose?​

• Beginner? Start with Web2 Bug Bounty
• Love crypto & complex logic? Go for Web3
• Want big payouts? Web3 = high risk, high reward
• Strong Web2 skills? Transition smoothly to Web3

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Pro Tip for Bug Hunters​

Most top Web3 bug bounty hunters started with Web2 first.
Strong web basics = bigger payouts later

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Learn More with Hack Training​

Bug bounty roadmaps
Real attack case studies
Web2 & Web3 security skills
Stay sharp. Hack smart