Countermeasures mitigation for designing rich shell code in Java card

Abstract

Recently, it has been published that Java based smart cards are still exposed to logical attacks. These attacks take advantage of the lack of a full verification and dynamically use a type of confusion. Countermeasures have been introduced on recent smart card to avoid executing rich shell code and particulary dynamic bound checking of the code segment. We propose here a new attack path for performing a type confusion that leads to a Java based self modifying code. Then, to mitigate this new attack an improvement to the previous countermeasure is proposed.