No Forking Way: Detecting Cloning Attacks on Intel SGX Applications
Samira Briongos, Ghassan Karame, Claudio Soriente, Annika Wilde · Annual Computer Security Applications Conference · 2023
Forking attacks against TEEs like Intel SGX can be carried out either by rolling back the application to a previous state, or by cloning the application and by partitioning its inputs across the cloned instances. Current solutions to forking attacks require Trusted Third Parties (TTP) that are hard to find in real-world deployments. In the absence of a TTP, many TEE applications rely on monotonic counters to mitigate forking attacks based on rollbacks; however, they have no protection mechanism against forking attack based on cloning. In this paper, we analyze 72 SGX applications and show that approximately 20% of those are vulnerable to forking attacks based on cloning—including those that rely on monotonic counters.