If a function was not designed to be reentrant, then merely sending money to a malicious third-party contract can break the function's intended preconditions an

If a function was not designed to be reentrant, then merely sending money to a malicious third-party contract can break the function's intended preconditions and result in a vulnerability. This is exactly what happened with the DAO exploit. http://hackingdistributed.com/2016/06/16/scanning-live-ethereum-contracts-for-bugs/ http://hackingdistributed.com/2016/06/16/scanning-live-ether...