EUSD.burnShares(address(receiver), burnShare);
function transferFrom(address from, address to, uint256 amount) public returns (bool) {
     address spender = _msgSender();
     if (!configurator. mintVault(spender)) {
         _spendAllowance(from, spender, amount);
     }
     _transfer(from, to, amount);
     return true;
}
contract GnosisSafeProxy {
    // singleton always needs to be first declared variable, to ensure that it is at the same location in the contracts to which calls are delegated.
    // To reduce deployment costs this variable is internal and needs to be retrieved via `getStorageAt`
    address internal singleton;

    /// @dev Constructor function sets address of singleton contract.
    /// @param _singleton Singleton address.
    constructor(address _singleton) {
        require(_singleton != address(0), "Invalid singleton address provided");
        singleton = _singleton;
    }

    /// @dev Fallback function forwards all transactions and returns all received return data.
    fallback() external payable {
        // solhint-disable-next-line no-inline-assembly
        assembly {
            let _singleton := and(sload(0), 0xffffffffffffffffffffffffffffffffffffffff)
            // 0xa619486e == keccak("masterCopy()"). The value is right padded to 32-bytes with 0s
            if eq(calldataload(0), 0xa619486e00000000000000000000000000000000000000000000000000000000) {
                mstore(0, _singleton)
                return(0, 0x20)
            }
            calldatacopy(0, 0, calldatasize())
            let success := delegatecall(gas(), _singleton, 0, calldatasize(), 0, 0)
            returndatacopy(0, 0, returndatasize())
            if eq(success, 0) {
                revert(0, returndatasize())
            }
            return(0, returndatasize())
        }
    }
}
[PASS] testGnosisSafeProxy() (gas: 10044)
Traces:
  [10044] AttackTest::testGnosisSafeProxy() 
     [4844] GnosisSafeProxy::onFlashLoan() 
        [0] 0xd9Db270c1B5E3Bd161E8c8503c55cEABeE709552::onFlashLoan() [delegatecall]
            ()
         ()
      ()

Test result: ok. 1 passed; 0 failed; finished in 972.63s
