Smart Contract Security Glossary
Definitions, examples, and audit checks for Solidity, EVM, and DeFi security terms.
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All glossary terms.
Vulnerabilities
7Reentrancy
Reentrancy is a smart contract vulnerability where external code calls back into a contract before the first call finishes, often before balances, ownership, or other state has been updated.
Read-Only Reentrancy
Read-only reentrancy happens when a view function returns stale or inconsistent state during an unfinished state transition, and another contract relies on that value.
Access Control Vulnerability
An access control vulnerability lets an unauthorized caller perform privileged actions such as moving funds, changing roles, upgrading contracts, or changing protocol settings.
Signature Replay
Signature replay happens when a valid signature can be reused more than once or reused in a different context than the signer intended.
Unchecked Return Value
An unchecked return value bug happens when code ignores whether a low-level call or token operation succeeded.
Weak Randomness
Weak randomness is predictable or manipulable randomness used for security-critical smart contract decisions.
Gas Griefing
Gas griefing is an attack or failure mode where a caller, receiver, or loop structure causes execution to fail by controlling gas usage.