CCA Security, Risk, and Vulnerabilities 3 — Questions and Answers
Question 1: What is a 'time-bandit' attack in the context of Proof-of-Work blockchains?
- Mining blocks faster using stolen hardware
- Rewriting recent blockchain history by bribing miners to reorganize profitable blocks (Correct answer)
- Using timestamps to manipulate smart contract execution
- Exploiting network latency to double-spend transactions
Correct answer: Rewriting recent blockchain history by bribing miners to reorganize profitable blocks
A time-bandit attack involves miners colluding to reorganize recent blocks to capture high-value MEV opportunities, destabilizing blockchain finality.
Question 2: Which vulnerability class does 'storage collision' in upgradeable proxy contracts fall under?
- Access control vulnerability
- Logic/storage layout conflict vulnerability (Correct answer)
- Oracle manipulation
- Signature replay vulnerability
Correct answer: Logic/storage layout conflict vulnerability
Storage collision occurs when proxy and implementation contracts use the same storage slots for different variables, causing data corruption during contract upgrades.
Question 3: An auditor is reviewing a DeFi protocol that uses a single on-chain price feed from a low-liquidity AMM. Which attack is this protocol most susceptible to?
- Reentrancy attack
- Flash loan price manipulation (Correct answer)
- Signature forgery
- Selfish mining
Correct answer: Flash loan price manipulation
Flash loans enable attackers to temporarily manipulate the price in a low-liquidity AMM within a single transaction, then exploit protocols relying on that manipulated price.
Question 4: What security risk does 'address poisoning' present to cryptocurrency users?
- DNS hijacking of exchange websites
- Sending dust transactions from look-alike addresses to trick users into copying the wrong recipient address (Correct answer)
- Injecting malicious code into wallet software
- Creating fake QR codes in public spaces
Correct answer: Sending dust transactions from look-alike addresses to trick users into copying the wrong recipient address
Address poisoning sends tiny transactions from addresses visually similar to frequent contacts, hoping users copy the attacker's address from their transaction history instead of the legitimate one.
Question 5: In a Proof-of-Stake system, what is 'long-range attack' and why is it a unique concern?
- Attacking nodes over long geographic distances to increase latency
- Using old private keys to rewrite blockchain history from a past point where an attacker had stake (Correct answer)
- Mining blocks for an extended period to accumulate enough hash power
- Gradually acquiring stake over a long timeframe to achieve 51%
Correct answer: Using old private keys to rewrite blockchain history from a past point where an attacker had stake
Long-range attacks exploit the fact that old private keys, once spent, can be used to rewrite history from a past checkpoint in PoS systems without requiring current stake.
Question 6: Which best describes 'key ceremony risk' in cryptocurrency custody operations?
- Risk of generating keys on internet-connected devices
- Risk of insider collusion or procedural failure during multi-party key generation events (Correct answer)
- Risk of using outdated cryptographic algorithms
- Risk of regulatory scrutiny during key management audits
Correct answer: Risk of insider collusion or procedural failure during multi-party key generation events
Key ceremonies involve multiple parties generating cryptographic material together; insider collusion, inadequate procedures, or environment compromise during this event can expose the keys.
Question 7: A cryptocurrency auditor discovers that a blockchain project's multi-sig wallet requires 2-of-3 signatures but all three signers are employees of the same company. What risk does this represent?
- Technical implementation risk due to incompatible signature schemes
- Governance concentration risk — regulatory or legal action against the company could disable all signers simultaneously (Correct answer)
- Liquidity risk due to slow multi-sig transaction processing
- Smart contract risk from outdated multi-sig implementation
Correct answer: Governance concentration risk — regulatory or legal action against the company could disable all signers simultaneously
When all signers share organizational affiliation, a single legal action, bankruptcy, or compromise of that organization can neutralize the multi-sig's distributed security model.
CCA Security, Risk, and Vulnerabilities 3
What is a 'time-bandit' attack in the context of Proof-of-Work blockchains?