What Is a Denial-of-Service (DoS) Attack Related to Fallback Functions?
A DoS attack related to fallback functions occurs when a malicious contract's fallback function is intentionally designed to consume excessive gas or always revert. If a vulnerable contract tries to send Ether to this malicious contract using transfer or send , the transaction will fail.
If the vulnerable contract relies on sending Ether to a list of users, the malicious contract can block the entire function for all other users.
Glossar
Nonreentrant Modifier
Vulnerability ⎊ A nonreentrant modifier, within the context of smart contract security in cryptocurrency, addresses a specific class of attack where a malicious actor exploits recursive calls to alter contract state unexpectedly.
DoS Attack
Mechanism ⎊ A Denial-of-Service (DoS) attack in this context is a malicious action designed to overwhelm a cryptocurrency network or a financial platform with excessive traffic or resource-intensive requests, thereby preventing legitimate users from accessing services.
Fallback Function
Contingency ⎊ A fallback function within cryptocurrency derivatives serves as a pre-defined operational protocol activated when primary system components, such as oracles or clearinghouses, experience disruptions or fail to deliver expected data or execution.