Blockchain Smart Contract Vulnerabilities

Question 1

What is a common vulnerability that allows repeated withdrawals in smart contracts?

Accepted Answer

Reentrancy

Answer

Race condition

Answer

Integer overflow

Answer

DoS attack

Question 2

Why is input validation critical in smart contracts?

Accepted Answer

To ensure logical correctness and safety

Answer

To improve transaction speed

Answer

To prevent contract duplication

Answer

To optimize gas usage

Question 3

Which vulnerability can allow funds to be locked indefinitely in a contract?

Accepted Answer

Fallback function flaw

Answer

Reentrancy

Answer

Timestamp dependency

Answer

Short address attack

Question 4

What is the purpose of using the 'checks-effects-interactions' pattern?

Accepted Answer

To defend against reentrancy attacks

Answer

To save gas

Answer

To handle overflow errors

Answer

To improve test coverage

Question 5

Which tool is commonly used to audit smart contracts for vulnerabilities?

Accepted Answer

MythX

Answer

GasNow

Answer

Chainlink

Answer

Metamask

Question 6

How can smart contracts defend against integer overflows?

Accepted Answer

Using SafeMath libraries

Answer

Avoiding arithmetic operations

Answer

Adding more gas to transactions

Answer

Limiting contract size