How Does a Reentrancy Attack Specifically Exploit Smart Contract Logic?
A reentrancy attack occurs when an external call from Contract A to Contract B is made, and Contract B then calls back into Contract A before A has finished updating its state, specifically the balance. This allows the attacker to recursively withdraw funds multiple times from the victim contract before the initial withdrawal transaction completes and the balance is properly reduced.
The classic defense involves using the Checks-Effects-Interactions pattern to update the state before making external calls.
Glossar
Reentrancy Attack
Exploit ⎊ The reentrancy attack, a critical vulnerability in smart contracts and financial systems, leverages recursive function calls to circumvent intended security protocols.
Gas Limitations
Constraint ⎊ Gas limitations, within cryptocurrency and derivatives markets, represent the computational cost associated with executing transactions or smart contracts on a blockchain network, directly impacting operational efficiency.
Exploit
Vulnerability ⎊ Within cryptocurrency, options trading, and financial derivatives, a vulnerability represents a systemic weakness in a protocol, smart contract, or trading infrastructure that can be leveraged to gain an unfair advantage or inflict financial harm.