Contactless fare cards in New Jersey and San Francisco transit systems can be manipulated using an Android application. The application takes advantage of a flaw found in particular NFC-based cards, the researchers said. The hack exploits the Mifare Ultralight chip used in disposable contactless NFC cards, they said. Boston, Seattle, Salt Lake City, Chicago and other U.S. cities also use a contactless ticketing system and those systems could also be vulnerable for the same technique. An adjusted version of the app, dubbed UltraCardTester, was made available for download by the researchers on Thursday.”]