A bridge mints or releases funds based on a cross-chain message whose validity (signatures, Merkle proof, guardian set) is improperly verified, letting an attacker forge deposit proofs and withdraw on the destination chain.
function release(bytes calldata m, bytes[] calldata sigs) external {
bytes32 h = keccak256(m);
require(!processed[h], "replayed");
require(_quorumValid(h, sigs), "insufficient sigs");
processed[h] = true; _payout(decode(m));
}
Incidents this entry cites by name:
Largest recorded losses in the same failure class — related, not the same bug:
The SaferICO scanner runs 201 detectors over your Solidity source, SAFE-0063 among them. Paste an address or the source itself — a small per-scan fee, shown before you sign, or unlimited on any plan.