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medium Logic / State SWC-132 CWE-664

Locked Ether — Receives ETH With No Withdraw Path

SAFE-0301 Logic / State Checked automatically by the scanner
1

What goes wrong

The contract can receive ETH (payable function, receive() or fallback()) but exposes no function that sends ETH out. Any Ether it accumulates is permanently trapped — no owner or user can ever recover it.

2

The vulnerable pattern

proof of concept — how it is exploited
// contract Vault { receive() external payable {} }  // no way out
// users send ETH; it is stuck forever — no withdraw / sweep function exists.
3

How to fix it

the pattern that is safe
function withdraw() external onlyOwner {
    (bool ok, ) = owner().call{value: address(this).balance}("");
    require(ok, "withdraw failed");
}
◆
Every contract that receives ETH needs an explicit withdrawal path.
4

Where this has happened

Largest recorded losses in the same failure class — related, not the same bug:

$586M · 2022 BNB Chain Token Hub Input validation · 2022 $326M · 2022 Wormhole Input validation · 2022 $197M · 2023 Euler Finance Input validation · 2023 $190M · 2022 Nomad Bridge Input validation · 2022
5

Related vulnerabilities in Logic / State

SAFE-0071Incorrect Accounting / Internal Balance Drift high · Logic / State SAFE-0095Uninitialized Storage Pointer (legacy) high · Logic / State SAFE-0146msg.value Reused Across a Loop / Multicall high · Logic / State SAFE-0249Missing Claimed Flag — Double Claim high · Logic / State SAFE-0070State Desync Between Related Variables medium · Logic / State SAFE-0081Storage vs Memory Misuse Causing State Bug medium · Logic / State SAFE-0093Selfdestruct Dependency / Forced Removal Assumption medium · Logic / State SAFE-0094Predictable Contract Address / CREATE2 Reorg Risk medium · Logic / State
← PreviousStorage Variable Read Repeatedly in a Loop
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