CBSE Blockchain System Testing 2

Question 1

Which testing technique is most effective for discovering re-entrancy vulnerabilities in smart contracts?

Accepted Answer

Fuzz testing with recursive call injection

Answer

Static code analysis

Answer

Load testing

Answer

Unit testing with mocked external calls

Question 2

A blockchain tester wants to verify that a node correctly enforces the longest-chain rule during a network partition. Which test environment best supports this?

Accepted Answer

Simulated network with configurable partition controls

Answer

Single-node testnet

Answer

Mainnet fork snapshot

Answer

Ganache in-memory blockchain

Question 3

During penetration testing of a blockchain node's RPC interface, which attack vector should be tested first?

Accepted Answer

Unauthenticated JSON-RPC method exposure

Answer

51% attack simulation

Answer

Eclipse attack

Answer

Sybil node injection

Question 4

What does a negative gas limit test in Ethereum smart contract testing verify?

Accepted Answer

That the EVM rejects transactions with an invalid or zero gas limit

Answer

That the contract reverts when gas exceeds the block limit

Answer

That miners can set arbitrary gas prices

Answer

That gas estimation tools return accurate values

Question 5

In a blockchain security audit, which property is verified by 'liveness testing'?

Accepted Answer

That the network eventually processes valid transactions

Answer

That node software cannot be remotely crashed

Answer

That private keys are stored securely

Answer

That block hashes are collision-resistant

Question 6

Which tool is specifically designed for automated security testing of Solidity smart contracts via symbolic execution?

Accepted Answer

Mythril

Answer

Truffle

Answer

Hardhat

Answer

Ganache

Question 7

A tester discovers that a DeFi protocol's oracle aggregator accepts a single data source. What vulnerability class does this represent?

Accepted Answer

Single point of failure / oracle manipulation

Answer

Denial of service

Answer

Integer overflow

Answer

Access control bypass