contract attack1 {
   function attack(address account, uint256 amount) {
         call attack2.forward(account, amount);
         call any other function of malt
  }
}

contract attack2 {
   function forward(address account, uint256 amount) {
       call bonding.bondToAccount(account, amount); // uses msg.sender of attack2
   }
}
function bondToAccount(address account, uint256 amount) public {
    if (msg.sender != offering) {
         _notSameBlock();
    }
    ...
function _notSameBlock() internal {
    require( block.number > lastBlock[_msgSender()],"Can't carry out actions in the same block" );
    lastBlock[_msgSender()] = block.number;
  }
