Web3 And Blockchain Security:Pen Testing & Bug Bounty Part1

Explore blockchain network attacks, including 51% attacks with hashing power and double spending, routing attack, front running, and transaction privacy leakage.

Explore consensus mechanism vulnerabilities in PoW and PoS, including 51% attacks, selfish mining, and double spending, plus nothing-to-stake forks, long-range attacks, and stake grinding.

Explore how oracle manipulation affects smart contracts by tampering data, manipulating data feeds, and targeting oracle infrastructure, causing financial loss and smart contract exploits.

Explore how denial-of-service attacks disrupt blockchains by flooding networks with high-volume traffic, transaction spam, and block spam, causing congestion, isolation of nodes, and economic losses.

Explore how smart contract reentrancy works, demonstrated with Remix and Truffle, including deposit and withdraw scenarios, attacker patterns, and protections like mutex, guard conditions, and call-stack checks.

Explore how integer overflow and underflow affect smart contracts, with unsigned and signed 8-bit examples, and learn to detect, prevent, and secure Ethereum contracts using safe math.

Explore how Solidity self-destruct vulnerabilities enable ether theft, illustrate an exploit contract, and outline defenses such as avoiding self-destruct, using transfer, and secure randomness with keccak-256 or block hash.

Examine cross-site scripting (XSS) in dapp interfaces and how attackers steal data or take control. Demonstrate sanitizing input, encoding output, and testing Burp Suite or Wasp Zap to prevent attacks.

Explore SQL injection in decentralized databases and how sqlmap automates detection and exploitation. Learn blind and time-based SQL injection techniques and basic defenses like input filters and wafs.

Learn how authentication bypass in web3 wallets can occur via MetaMask or Wallet Connect, the risks from compromised dapps and social engineering, and best practices to prevent unauthorized access.

Learn about front-end injection attacks in dApps and how JavaScript injection tools enable exploitation. Discover defenses like input sanitization, content security policy, https, and web application firewalls.

Explore how a denial-of-service vulnerability in Geth, the Go-based Ethereum client, triggers panics when nil nodes are processed and how explicit error checks prevent it.

Learn how gas price vulnerabilities in Ethereum enable front running, miner manipulation, and DDoS attacks through the gas guzzler concept and scripted examples.

Demonstrates how time-based attacks exploit block timestamps to bypass the lock period in smart contracts, using a time lock vault example with deposit and withdrawal.

explains replay attacks on cross-chain transactions, showing how an intercepted valid transfer can be replayed on another blockchain to lose funds, with a practical vulnerable contract demo and impact discussion.

Explain gas limit vulnerability on blockchain, where a contract loop exhausts gas and leads to a transaction failing with an out-of-gas error, yet users still incur gas costs.

explore blockchain reorganization attacks where forks occur, a longer chain with 51% of the hash rate discards competing blocks and reorganizes the ledger.

Explore supply chain attacks on blockchain, focusing on vulnerable Docker images and dependencies, where dependency confusion, malware, and insecure configurations can expose keys and compromise data.